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Thursday, February 23, 2012

World War II

Nazi Germany and Imperial Japan unleashed World War II with the intention of establishing, by military conquest, a permanent dominance over Europe and Asia respectively. These two nations were the most significant members of the Axispartnership, which was based on anti-Communism and dissatisfaction with the world order after World War I.
Under the leadership of dictator Adolf Hitler, Nazi Germany aimed at the acquisition of a vast, new empire of "living space" (Lebensraum) in eastern Europe and the Soviet Union. The Nazi leadership calculated that the realization of German hegemony in Europe would require war, and began planning a European war from the day the Nazis came to power in late January 1933.
Imperial Japan followed a policy of military conquest with support of its Emperor, military establishment, and many in the educated elite who sought Japanese rule and influence throughout East Asia and the Pacific Ocean. Germany and Japan formed an anti-Communist front aimed at the Soviet Union in 1936. That same year Fascist Italy and Nazi Germany formed the Axis alliance, shortly after Italy completed its brutal and successful conquest of Ethiopia.
Japan initiated its policy of military conquest by invading Chinese Manchuria in September 1931. Six years later, in July 1937, Japan invaded China proper to unleash World War II in Asia.
After incorporating Austria and the Czech lands without having to resort to war in 1938 and 1939 and securing the neutrality of the Soviet Union, ruled by dictator Joseph Stalin, with a pact of nonaggression, Germany invaded Poland. The invasion, on September 1, 1939, initiated World War II in Europe. Having permitted Nazi Germany to destroy the interwar Czechoslovak state, Britain and France had guaranteed the integrity of Poland's borders in April 1939. They responded to the German invasion of Poland by declaring war on Germany on September 3. Within a month, German and Soviet forces conquered Poland and partitioned the Polish state.
The lull which followed the defeat of Poland ended on April 9, 1940, when German forces invaded Norway and Denmark. Denmark surrendered that day. Norway held out until early June before German forces could occupy the entire country. On May 10, 1940, Germany began its assault on western Europe by invading France and the neutral Low Countries (theNetherlandsBelgium, and Luxembourg). The Low Countries were under German occupation by the end of May. On June 22, 1940, France signed an armistice with Germany. The armistice provided for the German occupation of the northern half of France and permitted the establishment of a collaborationist regime in the south with its seat in Vichy. From July 10 to October 31, 1940, the Germans waged, and ultimately lost, an air war over England, known as the Battle of Britain.
In accordance with sphere of influence arrangements with Nazi Germany in 1939, the Soviet Union invaded Finland at the end of November 1939. After a bitterly fought winter war, the Soviets forced the Finns to cede territory along the northern shores of Lake Lagoda north of Leningrad (St. Petersburg) and on the Arctic coastline in March 1940. With German encouragement, the Soviet Union occupied the Baltic states in June 1940 and annexed them in August 1940. The Soviets also seized Bessarabia and northern Bukovina from Romania in late June 1940.
Italy entered the war on June 10, 1940, and invaded southern France on June 21. Dissatisfied with Italy's share in the spoils at the armistice negotiations, Fascist dictator Benito Mussolini attacked Greece in October 1940 from Albania (which the Italians had seized in April 1939). The Italians also attacked British forces in Egypt from Italian-controlled Libya in late October 1940. Both adventures resulted in military disaster that required German intervention.
Germany enticed Hungary, Romania, and Slovakia in November 1940 and Bulgaria in March 1941 to join the Axis. In April 1941, Germany -- supported by Italy, Hungary and Bulgaria -- invaded and dismembered Yugoslavia. By mid-June, the Axis powers had subdued Greece. Out of the collapse of Yugoslavia arose the so-called Independent State of Croatia under the leadership of the fascist and terrorist Ustasa organization. The new state, which encompassed Bosnia and Herzegovina, formally joined the Axis on June 15. Germany occupied eastern Slovenia, the Serbian Banat and most of Serbia proper. Italy seized Istria and western Slovenia, attached Kosovo province to Albania, and occupied the Croat-Dalmatian coastline and Montenegro. Hungary annexed Backa in northeastern Yugoslavia, and Bulgaria occupied Macedonia and the Pirot province of Serbia. After permitting Bulgaria to occupy Greek Thrace, Germany and Italy divided Greece into occupation zones, with the Italians in the west and the Germans in the east.
On June 22, 1941, the Germans and their Axis partners (except Bulgaria) invaded the Soviet Union in direct violation of the German-Soviet Pact of August 1939. Finland, seeking redress for its defeat in the winter war of 1939-1940, joined the Axis and the German invasion. By the end of October 1941, German troops had advanced deep into the Soviet Union, overrunning the Baltic states and laying siege to Leningrad in the north; capturing Smolensk and marching on Moscow in the center; and capturing Kiev (Kyiv) and approaching Rostov on the mouth of the Don River in the south. Stiffening Red Army resistance in August and again in November 1941 prevented the Germans from capturing the key cities of Leningrad and Moscow. On December 6, 1941, Soviet troops launched a significant counteroffensive that drove the Germans permanently from the outskirts of Moscow.
One day later, on December 7, 1941, Japan, still engaged in warfare on the Chinese mainland, launched a surprise air attack on Pearl Harbor, Hawaii. The United States immediately declared war on Japan. Great Britain followed suit. On December 11, Germany and Italy declared war on the United States. During the winter of 1941-1942, the Japanese attacked and conquered the Philippines, French Indochina (Vietnam, Laos, and Cambodia), and British Singapore. In the late spring and early summer of 1942, the British were able to halt the Japanese advance in Burma; and the U.S. soundly defeated the Japanese navy at Midway in the Pacific. In August 1942, U.S. forces halted the Japanese advance in the Pacific islands towards Australia at Guadalcanal in the Solomon Islands.
In May 1942, the British Royal Air Force carried out a raid on the German city of Köln (Cologne) with a thousand bombers, for the first time bringing war home to Germany. For the next three years, Allied air forces systematically bombed industrial plants and cities all over the Reich, reducing much of urban Germany to rubble by 1945.
In late 1942 and early 1943, Anglo-American forces achieved a series of significant military triumphs in North Africa. The failure of Vichy French armed forces to resist enabled the Allies to quickly occupy French North Africa to the Tunisian border within days of landings on the beaches of Morocco and Algeriaon November 8, 1942. It also triggered the German occupation of Vichy France on November 11, 1942. The British victory over the German Afrika Korps at El Alamein in Egypt in late October 1942 precipitated the flight of Axis military units west across Libya into eastern Tunisia. Trapped in Tunisia, the Axis forces in Africa, approximately 150,000 troops in all, surrendered in May 1943.
In June 1942, the Germans and their Axis partners resumed their offensive in the Soviet Union, reaching Stalingrad (Volgograd) on the Volga River, securing the Crimean peninsula, and penetrating deep into the Caucasus region by late September 1942. In November, Soviet troops launched a counteroffensive northwest and southwest of Stalingrad that cut off the German forces in the city. On February 2, 1943, the German Sixth Army surrendered to the Soviets. The Germans mounted one more offensive at Kursk in July 1943, the biggest tank battle in history, but Soviet troops and tanks blunted the attack and assumed a military initiative that they would not again relinquish. By late 1943, the Germans were forced to evacuate the Caucasus and to relinquish Kiev.
In July 1943, the western Allies successfully landed in Sicily. This precipitated the decision of the Italian Fascist Party Grand Council to depose Mussolini. Led by Field Marshall Pietro Badoglio, the Italian Army took advantage of the political vacuum to overthrow the Fascist regime, replacing it with a military dictatorship. In early September, just prior to the landing of Anglo-American forces in Salerno near Naples, the Badoglio government surrendered unconditionally to the Allies on September 8. German troops stationed in Italy seized control of northern Italy, and continued to resist. Mussolini, who had been arrested by Italian military authorities, was rescued by SS commandos in September and established (under German supervision) a neo-Fascist puppet regime in northern Italy.
The Allies successfully landed near Anzio, just south of Rome, but were not able to capture Rome until early June 1944. German troops continued to occupy northern Italy, and resisted tenaciously until they surrendered on May 2, 1945. After the liberation of Rome, Allied air forces could bomb German targets in eastern Europe, such as the synthetic fuel and rubber plants at Auschwitz-Monowitz in Silesia.
On June 6, 1944 (D-Day), over 150,000 Allied soldiers landed on the Normandy beaches of France. Trapped on the Normandy coast for six weeks, the British and Americans broke loose on July 25 and liberated Paris by August 25. On September 11, 1944, the first U.S. troops crossed into Germany. By December, all of France, most of Belgium, and part of the southern Netherlands had been liberated.
On June 22, 1944, Soviet forces destroyed the German Army Group Center in Eastern Belorussia. They swept west to the Vistula River across from Warsaw by August 1, 1944. In early August, Soviet troops, having conquered the eastern Romanian province of Bessarabia, appeared on the Prut River and prepared to strike into the heart of Romania, precipitating a Romanian surrender on August 23. The Bulgarians surrendered on September 8, 1944. These developments forced the Germans to evacuate Greece, Albania, and southern Yugoslavia. To forestall Hungarian government efforts to pursue a separate peace, Germany had occupied Hungary on March 19, 1944. Germany had then, in October, sponsored a coup d'état of the radical Arrow Cross Party to prevent another Hungarian effort to surrender. Finally, the appearance of Soviet troops on the Finnish border induced the Finns to sue for an armistice on September 12, 1944. In August 1944, the underground Polish Home Army and the Slovak National resistance organizations rose against the Germans to liberate Warsaw and Slovakia from German rule; the Germans were able to quell both uprisings.
On December 16, 1944, the Germans launched an unsuccessful counterattack in Belgium and northern France, known as the Battle of the Bulge. By New Year's Day, British and U.S. troops had driven the Germans back into Germany. On January 12, 1945, the Soviets resumed the offensive, liberating Warsaw and western Poland. In December the Soviets had encircled Budapest, though the city did not fall until February 13, 1945. By early April, the Soviets had driven the remnants of the Arrow Cross regime out of Hungary and forced the surrender of the fascist Slovak Republic with the fall of Bratislava on April 4, 1945. On April 13, the Soviets captured Vienna, while Marshall Josip Tito's Partisans compelled the flight of the Ustasa leaders and the collapse of the so-called Independent State of Croatia.
In mid-February 1945, the Allies bombed Dresden, killing approximately 35,000 German civilians. U.S. troops crossed the Rhine River at Remagen on March 7, 1945. A final Soviet offensive on April 16, 1945, enabled Soviet forces to encircle Berlin. As Soviet troops fought their way towards the Reich Chancellery, Hitler committed suicide on April 30, 1945. On May 7, 1945, Germany surrendered unconditionally to the western Allies at Reims and on May 9 to the Soviets in Berlin.
After clearing the Japanese from the Solomon Islands in November 1942, British and U.S. forces began slowly to move northward, island-hopping toward the Japanese mainland, while British forces worked with the Nationalist Chinese government to fight the Japanese in China. In a parallel campaign, the Chinese Communist movement fought the Japanese, while it defended itself against attacks from the Nationalists. In October 1944, U.S. troops landed in the Philippines; by May 1945, British and U.S. troops had conquered Okinawa, the last major Japanese base before the mainland itself. On August 6, 1945, the United States dropped the first atomic bomb on Hiroshima, following with a second atomic bomb on Nagasaki on August 9. On August 8, the Soviet Union declared war on Japan and invaded Japanese-occupied Manchuria. Less than a week later, on August 14, 1945, Japan agreed to surrender; the formal ceremony took place on September 2. World War II was over.
World War II resulted in an estimated 55 million deaths worldwide. While many of the following statistics are subject to variation in the available source material, they serve as benchmarks for estimates. In battle, the United States lost 292,129 dead and 139,709 missing in action. The Soviet Union suffered 8,668,400 dead and another 4,559,000 missing. Germany lost 2,049,872 dead and 1,902,704 missing. China lost 1,324,516 dead and 115,248 missing. Japan lost 1,506,000 dead and 810,000 missing. Great Britain lost 397,762 dead and 90,188 missing.
The large number of civilian dead was equally appalling. The Soviet Union lost 14,012,000 civilians, including between 1.0 and 1.5 million Jews. China lost more than a million civilians; while Poland lost nearly five million civilians, including nearly three million Jews.
The Holocaust took place in the broader context of World War II. Still reeling from Germany's defeat in World War I, Hitler's government envisioned a vast, new empire of "living space" (Lebensraum) in eastern Europe. The realization of German dominance in Europe, its leaders calculated, would require war.
1939
After securing the neutrality of the Soviet Union (through the August 1939German-Soviet Pact of nonaggression), Germany started World War II by invading Poland on September 1, 1939. Britain and France responded by declaring war on Germany on September 3. Within a month, Poland was defeated by a combination of German and Soviet forces and was partitioned between Nazi Germany and the Soviet Union.
1940
The relative lull in fighting which followed the defeat of Poland ended on April 9, 1940, when German forces invaded Norwayand Denmark. On May 10, 1940, Germany began its assault on western Europe by invading the Low Countries (Netherlands, Belgium, and Luxembourg), which had taken neutral positions in the war, as well as France. On June 22, 1940, France signed an armistice with Germany, which provided for the German occupation of the northern half of the country and permitted the establishment of a collaborationist regime in the south with its seat in the city of Vichy.
With German encouragement, the Soviet Union occupied the Baltic states in June 1940 and formally annexed them in August 1940. Italy, a member of the Axis (countries allied with Germany), joined the war on June 10, 1940. From July 10 to October 31, 1940, the Nazis waged, and ultimately lost, an air war over England, known as the Battle of Britain.
1941
After securing the Balkan region by invading Yugoslavia and Greece on April 6, 1941, the Germans and their allies invaded the Soviet Union on June 22, 1941, in direct violation of the German-Soviet Pact. In June and July 1941, the Germans also occupied the Baltic states. Soviet leader Joseph Stalin then became a major wartime Allied leader, in opposition to Nazi Germany and its Axis allies. During the summer and autumn of 1941, German troops advanced deep into the Soviet Union, but stiffening Red Army resistance prevented the Germans from capturing the key cities of Leningrad and Moscow. On December 6, 1941, Soviet troops launched a significant counteroffensive that drove German forces permanently from the outskirts of Moscow. One day later, on December 7, 1941, Japan (one of the Axis powers) bombed Pearl Harbor, Hawaii. The United States immediately declared war on Japan. On December 11, Germany and Italy declared war on the United States as the military conflict widened.
1942-1943
In May 1942, the British Royal Air Force carried out a raid on the German city of Cologne with a thousand bombers, for the first time bringing war home to Germany. For the next three years, Allied air forces systematically bombed industrial plants and cities all over the Reich, reducing much of urban Germany to rubble by 1945. In late 1942 and early 1943, the Allied forces achieved a series of significant military triumphs in North Africa. The failure of French armed forces to prevent Allied occupation of Morocco and Algeria triggered a German occupation of collaborationist Vichy France on November 11, 1942. Axis military units in Africa, approximately 150,000 troops in all, surrendered in May 1943.
On the eastern front, during the summer of 1942, the Germans and their Axis allies renewed their offensive in the Soviet Union, aiming to capture Stalingrad on the Volga River, as well as the city of Baku and the Caucasian oil fields. The German offensive stalled on both fronts in the late summer of 1942. In November, Soviet troops launched a counteroffensive at Stalingrad and on February 2, 1943, the German Sixth Army surrendered to the Soviets. The Germans mounted one more offensive at Kursk in July 1943, the biggest tank battle in history, but Soviet troops blunted the attack and assumed a military predominance that they would not again relinquish during the course of the war.
In July 1943, the Allies landed in Sicily and in September went ashore on the Italian mainland. After the Italian Fascist Party's Grand Council deposed Italian premier Benito Mussolini (an ally of Hitler), the Italian military took over and negotiated a surrender to Anglo-American forces on September 8. German troops stationed in Italy seized control of the northern half of the peninsula, and continued to resist. Mussolini, who had been arrested by Italian military authorities, was rescued by German SS commandos in September and established (under German supervision) a neo-Fascist puppet regime in northern Italy. German troops continued to hold northern Italy until surrendering on May 2, 1945.
1944
On June 6, 1944 (D-Day), as part of a massive military operation, over 150,000 Allied soldiers landed in France, which was liberated by the end of August. On September 11, 1944, the first US troops crossed into Germany, one month after Soviet troops crossed the eastern border. In mid-December the Germans launched an unsuccessful counterattack in Belgium and northern France, known as the Battle of the Bulge. Allied air forces attacked Nazi industrial plants, such as the one at the Auschwitz camp (though the gas chambers were never targeted).
1945
The Soviets began an offensive on January 12, 1945, liberating western Poland and forcing Hungary (an Axis ally) to surrender. In mid-February 1945, the Allies bombed the German city of Dresden, killing approximately 35,000 civilians. American troops crossed the Rhine River on March 7, 1945. A final Soviet offensive on April 16, 1945, enabled Soviet forces to encircle the German capital, Berlin. As Soviet troops fought their way towards the Reich Chancellery, Hitler committed suicide on April 30, 1945. On May 7, 1945, Germany surrendered unconditionally to the Western Allies at Reims and on May 9 to the Soviets in Berlin. In August, the war in the Pacific ended soon after the US dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, killing 120,000 civilians. Japan formally surrendered on September 2.
World War II resulted in an estimated 55 million deaths worldwide. It was the largest and most destructive conflict in history.
Further Reading
Berthon, Simon, and Joanna Potts. Warlords: An Extraordinary Re-Creation of World War II Through the Eyes and Minds of Hitler, Churchill, Roosevelt, and Stalin. Cambridge, MA: Da Capo Press, 2006.
Bess, Michael. Choices Under Fire: Moral Dimensions of World War II. New York: A.A. Knopf, 2006.
Chickering, Roger, Stig Fo¨rster, and Bernd Greiner. A World at Total War: Global Conflict and the Politics of Destruction, 1937-1945. Washington, DC: German Historical Institute, 2005.
Plowright, John. The Causes, Course, and Outcomes of World War Two. England: Palgrave Macmillan, 2007.
Weinberg, Gerhard L. Hitler's Foreign Policy: The Road to World War II, 1933-1939. New York: Enigma, 2005.






























Thanks http://www.ushmm.org/wlc/en/article.php?ModuleId=10007314

An animated introduction to the UN's Global Pulse initiative

                         Global Pulse (www.unglobalpulse.org) is an innovation initiative of the UN Secretary-General, harnessing today's new world of digital data and real-time analytics to gain a better understanding of changes in human well-being.

Learn more at www.unglobalpulse.org

Production Development: Christine Outram, Peter Hirshberg, Anoush Rima Tatevossian
Animation: Filippo Camedda
Voice Over: Alice Kariuki
Voice Editing: Rosie Starr

How Social Networks Improve Your Health



My neighbour, who is 44, just suffered a heart attack and underwent triple bypass surgery. His wife, with two young children, was understandably in a state of shock. We rallied around with home-cooked heart-healthy meals and helped with exercise. My family stepped up because we knew that our neighbours, without close relatives locally, could use our help and support.

So, I felt a sense of connection when I read Mark Hyman’s recent article in the Huffington Post on how communities are often the best medicine for change.  He pointed out that the secret of an effective model for treating drug-resistant TB and AIDS in Haiti lay not in new drugs or medical centres but in the community. He notes, “Recruiting and training over 11,000 community health workers across the world…proved that the sickest, poorest patients with the most difficult to treat diseases in the world could be successfully treated. The community was the treatment…”

Community healthcare programs are not a new idea, but people use this concept innovatively. For example, a post on Poverty Matters describes how training community workers to provide mental health support can make a huge difference in impoverished communities where primary health care is scarce. The Manas trial found that patients receiving such care showed a 30 per cent decrease in common mental disorders.

In fact, as Hyman notes, “Much can be done with a little help from your friends.” He says, “Facebook and Twitter can not only help facilitate a democratic revolution in countries like Egypt, but they can also link communities together in a common purpose to reclaim their health. Think ‘Occupy Health Care’ or ‘Wellness Spring.’”

Now, there’s a revolution that can bring about positive change.



The Employees First Effect

                                        When faced with one of the toughest recessions in recent history, HCL Technologies turned its organization upside down and became one of the fastest growing companies in the world. At HCL, we call this movement Employees First -- and we believe that it is the only path to strong, sustainable growth in these turbulent times.

Visit HCLTechtube for more videos from HCL Technologies or visit www.hcltech.com to know more about Employees First.

Credits
Creative Agency: Wieden+Kennedy Delhi 
Executive Creative Director: V Sunil 
Creative: Akash Das and Sundar Iyer
Account Management: Tushar Mehta and Ankit Kumar
Director: Bharat Sikka
Production House: Flying Pigs Production

Full Script

It's 8 am.

Millions of employees show up each day, to put their names on a register. The world we see around us... countries and continents, have been built on the back of these signatures. The future too, will be written by these signatures - signatures of employees.

You are an employee 

Your boss is an employee

The cable guy is an employee 

The overworked... the unsung

The white collared... the blue collared

The Father of a nation 

Fathers and mothers, sons and daughters 

Healers and protectors 

The girl you will fall in love with 

The graveyard shift veterans

Even Chief Executives 

...actors, spot boys

Master-chefs and waitresses 

...truth is we are all employees, putting our names on ideas that shape our world. 

Truth is... every employee is a hero.

Enough said. Let's go do what we all do best.

Let's go to work.

Heart Beats to the Rhythm of a Circadian Clock




Science Daily — Sudden cardiac death -catastrophic and unexpected fatal heart stoppage -- is more likely to occur shortly after waking in the morning and late at night.

In a report in the journal Nature, an international consortium of researchers that includes Case Western Reserve University School of Medicine in Cleveland and Baylor College of Medicine explains the molecular linkage between the circadian clock and the deadly heart rhythms that lead to sudden death.
The answer begins with a controller of the circadian clock -- krüppel-like factor 15 (Klf15), which has been a long-time target of the laboratory of Dr. Mukesh Jain of Case Western, said Dr. Xander Wehrens, professor of molecular physiology and biophysics and cardiology at BCM, also an author.
Klf15, in turn, controls the level of a potassium channel-interacting protein (KChIP2), which affects how potassium flows out of heart muscle cells called cardiac myocytes.
Changes affect potassium current.
Because the level of this KChIP2 protein fluctuates during the circadian or daily cycle, it can change the size of the potassium current in cardiac myocytes. Changes in this subunit or Klf15, can affect the potassium current that governs repolarization of the cardiac myocyte. Overall, this can shorten or lengthen the heart muscle has time to empty the heart's pumping chamber (ventricle) of blood. This time interval for repolarization is critical. Too much or too little can result in abnormal heart rhythms called arrhythmias. As the heart loses the regularity of the beat, it cannot pump blood efficiently.
Studies of mice that lacked Klf15 and mice with a genetic change that caused them to make more Klf15 than normal increased the risk of deadly arrhythmias.
This was a proof of principle, said Wehrens.
"It is the first example of a molecular mechanism for the circadian change in susceptibility to cardiac arrhythmias," he said.
"If there was too much Klf15 or none, the mice were at risk for developing the arrhythmias," he said.
Long QT or Short QT
Because Klf15 is regulated by the circadian "clock," the rate of flow through the potassium channel goes up and down and if disrupted, can lead to a change that results in one of two known heart problems linked to sudden death -- long QT or short QT syndrome. (QT refers to an interval measured from an electrocardiogram or ECG, which corresponds to the electrical recovery time of the heart.)
Wehrens credits Jain's laboratory with accomplishing much of the work. He said that his laboratory performed the electrophysiology experiments with the mice that lacked Klf15 and those who produced too much.
Much of the BCM work was done by Dr. Mark McCauley, a cardiology fellow who was a post-doctoral fellow in the laboratory at the time, said Wehrens.
Others who took part in this work include first author Darwin Jeyaraj, Saptarsi Haldar, Xiapoing Wan, Yuan Lu, Betty Eapen, Nikunj Sharma, Eckhard Ficker, Michael Cutler, and David Rosenbaum, all of Case Western; Jurgen A. Ripperger and Urs Albrecht of University of Fribourg in Switzerland; Kun Hu and Steven A. Shea of Brigham and Women's Hospital and Harvard Medical School in Boston; James Gulick, Atusushi Sanbe, and Jeffrey Robbins of Cincinnati Children's Hospital Medical Center; Sophie Demolombe of Universite de Nice Sophia Antipolis in Valbonne, France; and Roman Kondratov of Cleveland State University in Ohio.
Funding for this work came from the National Institutes of Health, the Heart Rhythm Society, the American Heart Association, the Swiss National Science Foundation, the Centre National de la Recherche Scientifique, and the Leducq Foundation.

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Tiny, Implantable Medical Device Can Propel Itself Through Bloodstream


Engineers at Stanford have developed a wirelessly powered, self-propelled medical device that can propel itself through the blood stream to deliver drugs, perform diagnostics or microsurgeries. (Credit: Illustration by Carlos Suarez, StrongBox3d)                                                                    Science Daily — For 50 years, scientists had searched for the secret to making tiny implantable devices that could travel through the bloodstream. Engineers at Stanford have demonstrated a wirelessly powered device that just may make the dream a reality.

Someday, your doctor may turn to you and say, "Take two surgeons and call me in the morning." If that day arrives, you may just have Ada Poon to thank.
Yesterday, at the International Solid-State Circuits Conference (ISSCC) before an audience of her peers, electrical engineer Poon demonstrated a tiny, wirelessly powered, self-propelled medical device capable of controlled motion through a fluid -- blood more specifically. The era of swallow-the-surgeon medical care may no longer be the stuff of science fiction.
Poon is an assistant professor at the Stanford School of Engineering. She is developing a new class of medical devices that can be implanted or injected into the human body and powered wirelessly using electromagnetic radio waves. No batteries to wear out. No cables to provide power.
"Such devices could revolutionize medical technology," said Poon. "Applications include everything from diagnostics to minimally invasive surgeries."
Certain of these new devices, like heart probes, chemical and pressure sensors, cochlear implants, pacemakers, and drug pumps, would be stationary within the body. Others, like Poon's most recent creations, could travel through the bloodstream to deliver drugs, perform analyses, and perhaps even zap blood clots or removing plaque from sclerotic arteries.
Challenged by power
The idea of implantable medical devices is not new, but most of today's implements are challenged by power, namely the size of their batteries, which are large, heavy and must be replaced periodically. Fully half the volume of most of these devices is consumed by battery.
"While we have gotten very good at shrinking electronic and mechanical components of implants, energy storage has lagged in the move to miniaturize," said co-author Teresa Meng, a professor of electrical engineering and of computer science at Stanford. "This hinders us in where we can place implants within the body, but also creates the risk of corrosion or broken wires, not to mention replacing aging batteries."
Poon's devices are different. They consist of a radio transmitter outside the body sending signals to an independent device inside the body that picks up the signal with an antenna of coiled wire. The transmitter and the antenna are magnetically coupled such that any change in current flow in the transmitter produces a voltage in the coiled wire -- or, more accurately, itinduces a voltage. The power is transferred wirelessly. The electricity runs electronics on the device and propels it through the bloodstream, if so desired.
Upending convention
It sounds easy, but it is not. Poon had to first upend some long-held assumptions about the delivery of wireless power inside the human body.
For fifty years, scientists have been working on wireless electromagnetic powering of implantable devices, but they ran up against mathematics. According to the models, high-frequency radio waves dissipate quickly in human tissue, fading exponentially the deeper they go.
Low-frequency signals, on the other hand, penetrate well, but require antennae a few centimeters in diameter to generate enough power for the device, far too large to fit through all but the biggest arteries. In essence, because the math said it could not be done, the engineers never tried.
Then a curious thing happened. Poon started to look more closely at the models. She realized that scientists were approaching the problem incorrectly. In their models, they assumed that human muscle, fat and bone were generally good conductors of electricity, and therefore governed by a specific subset of the mathematical principles known as Maxwell's equations -- the "quasi-static approximation" to be exact.
Poon took a different tack, choosing instead to model tissue as a dielectric -- a type of insulator. As it turns out human tissue is a poor conductor of electricity. But, radio waves can still move through them. In a dielectric, the signal is conveyed as waves of shifting polarization of atoms within cells. Even better, Poon also discovered that human tissue is a "low-loss" dielectric -- that is to say little of the signal gets lost along the way.
She recalculated and made a surprising find: Using new equations she learned high-frequency radio waves \ travel much farther in human tissue than originally thought.
Revelation
"When we extended things to higher frequencies using a simple model of tissue we realized that the optimal frequency for wireless powering is actually around one gigahertz," said Poon, "about 100 times higher than previously thought."
More significantly, however, her revelation meant that antennae inside the body could be 100 times smaller and yet deliver the same power.
Poon was not so much in search of a new technology; she was in search of a new math. The antenna on the device Poon demonstrated at the conference yesterday is just two millimeters square; small enough to travel through the bloodstream.
She has developed two types of self-propelled devices. One drives electrical current directly through the fluid to create a directional force that pushes the device forward. This type of device is capable of moving at just over half-a-centimeter per second. The second type switches current back-and-forth in a wire loop to produce swishing motion similar to the motion a kayaker makes to paddle upstream.
"There is considerable room for improvement and much work remains before these devices are ready for medical applications," said Poon. "But for the first time in decades the possibility seems closer than ever."
Stanford doctoral candidates Daniel Pivonka and Anatoly Yakovlev contributed to this research.
Ada Poon's research was made possible by the support of C2S2 Focus Center, Olympus Corporation, and Taiwan Semiconductor Manufacturing Company.

Off Switch for Pain? Chemists Build Light-Controlled Neural Inhibitor


In a new study, researchers report they have now succeeded in inhibiting pain-sensitive neurons on demand, in the laboratory. (Credit: © Jule_Berlin / Fotolia)                                   Science Daily  — Pain? Just turn it off! It may sound like science fiction, but researchers based in Munich, Berkeley and Bordeaux have now succeeded in inhibiting pain-sensitive neurons on demand, in the laboratory. The crucial element in their strategy is a chemical sensor that acts as a light-sensitive switch.

The notion of a pain switch is an alluring idea, but is it realistic? Well, chemists at LMU Munich, in collaboration with colleagues in Berkeley and Bordeaux, have now shown in laboratory experiments that it is possible to inhibit the activity of pain-sensitive neurons using an agent that acts as a photosensitive switch. For the LMU researchers, the method primarily represents a valuable tool for probing the neurobiology of pain.
The system developed by the LMU team, led by Dirk Trauner, who is Professor of Chemical Biology and Genetics, is a chemical compound they call QAQ. The molecule is made up of two functional parts, each containing a quaternary ammonium, which are connected by a nitrogen double bond (N=N). This bridge forms the switch, as its conformation can be altered by light. Irradiation with light of a specific wavelength causes the molecule to flip from a bent to an extended form; exposure to light of a different color reverses the effect.
One half of QAQ closely resembles one of the active analogs of lidocaine, a well-known local anesthetic used by dentists. Lidocaine blocks the perception of pain by inhibiting the action of receptors found on specific nerve cells in the skin, which respond to painful stimuli and transmit signals to the spinal cord.
Neuroreceptors are proteins that span the outer membrane of nerve cells. They possess deformable pores that open in response to appropriate stimuli, and function as conduits that permit electrically charged ions to pass into or out of the cells. The ion channel targeted by the lidocaine-like end of QAQ responds to heat by allowing positively charged sodium ions to pass into the cells that express it. This alters the electrical potential across the membrane, which ultimately leads to transmission of the nerve impulse.
In their experiments, the researchers exploited the fact that QAQ can percolate through endogenous ion channels to get the molecule into nerve cells. This is a crucial step, because its site of action is located on the inner face of the targeted ion channel.
Furthermore, the lidocaine-like end of QAQ binds to this site only if the molecule is in an extended conformation. When the cells were irradiated with 380-nm light, which bends the bridge, signal transmission was reactivated within a matter of milliseconds. Exposure to light with a wavelength of 500 nm, on the other hand, reverts the molecule to the extended form and restores its inhibitory action. The analgesic effect of the switch was confirmed using an animal model.
Trauner's team has been working for some considerable time on techniques with which biologically critical molecular machines such as neuroreceptors can be controlled in living animals by means of light impulses. The researchers themselves regard the new method primarily as a tool for neurobiological studies, particularly for pain research. Therapeutic applications of the principle are "a long way off," says Timm Fehrentz, one of Dirk Trauner's PhD students and one of the two equal first authors on the new paper. For one thing, the monochromatic light used to isomerize the QAQ molecule cannot penetrate human skin sufficiently to reach the pain-sensitive neurons. The researchers hope to address that problem by looking for alternatives to QAQ that respond to red light of longer wavelength, which more readily passes through the skin.