【Native Speaker每日综合训练—43系列】【43-10】科技 Blood

Cassidy大洁洁

内容：Cassidy大洁洁 编辑：Cassidy大洁洁

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Part I:Speaker

Carnivorous Plant Inspires Anticlotting Medical Devices

Medical devices like implanted arteries or external dialysis machines keep people alive. But persistent problems exist. Blood flowing through the tubes can form dangerous clots. And bacteria that stick to surfaces could start infections.

Treatment for patients using such devices thus often includes anticlotting agents such as heparin. But such substances have their own risk: by interfering with clotting, they can cause potentially deadly bleeding.

Recently, researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University looked to the carnivorous pitcher plant for guidance. The plant’s structure includes wells with surfaces too slippery for insects to crawl out of. Those surfaces inspired the development of a coating so slippery that it prevents blood and bacteria from sticking.

The team tested the coating on the interiors of tubes and catheters attached to pigs. They demonstrated that the coating did not degrade, and that blood kept flowing without clotting, for eight hours. Blood usually starts to clot in tubes in an hour. The study is in the journal Nature Biotechnology. [Daniel C. Leslie et al, A bioinspired omniphobic surface coating on medical devices prevents thrombosis and biofouling]

The researchers also tested whether a gecko could latch onto the coating with its notoriously sticky footpads. But not even the gecko could get a grip.

Source: Scientifc American
http://www.scientificamerican.com/podcast/episode/carnivorous-plant-inspires-anticlotting-medical-devices/

Cassidy大洁洁

Part II: Speed

High blood pressure increases risk of stroke for atrial fibrillation patients
Date: March 30, 2014
Source: Duke Medicine

[Time 2]
Poor blood pressure control among patients with atrial fibrillation is associated with a 50-percent increased risk of stroke, according to an analysis presented by Duke Medicine researchers.

The findings, presented in a poster Saturday, March 29, 2014, at the American College of Cardiology meeting in Washington, D.C., suggest that hypertension should be carefully monitored and controlled among patients with atrial fibrillation.

Using data from a large clinical trial called ARISTOTLE, the Duke researchers analyzed more than 18,000 patients with atrial fibrillation to understand how high blood pressure affects their health.

Strokes were more common in atrial fibrillation patients who had a history of high blood pressure, or who had high blood pressure at the start of the study. A significant increase in the risk of stroke was also seen in patients who had high blood pressure measurements at any point during the study.

“This study is unique in that we looked at patients with atrial fibrillation who had a history of high blood pressure, patients who had high blood pressure measurement at the start of the study, and blood pressure control during the course of the study,” said lead author Meena Rao, M.D., MPH, research fellow at the Duke Clinical Research Institute.

“We found that having high blood pressure at any point during the trial led to an increased risk of stroke by approximately 50 percent in patients with atrial fibrillation,” Rao said. “This highlights the importance of blood pressure control in addition to anticoagulation to reduce the risk of stroke in patients with atrial fibrillation.”
[256 words]

Source: Science Daily
http://www.sciencedaily.com/releases/2014/03/140330151245.htm


Can Compounds in Young Blood Fix Aging?
By Susan Young Rojahn on May 9, 2014

[Time 3]
Researchers and investors are already dreaming up ways to devise medical treatments based on the near-fantastical findings that the blood of young mice can rejuvenate older mice. In some cases, a single protein found circulating in the blood is sufficient to restore muscle tissue and improve brain activity.

The excitement is spurred by three newly published studies that showed that components of blood from young mice were able to repair damage and improve the function of the muscles and brains of older mice. Previous work from one of the research teams involved has also shown that a specific component of young blood can repair the damaged hearts of older mice.

“We started this work more than a decade ago, with a kind-of crazy hypothesis that there might be something in the blood that influences tissue repair with age,” says Amy Wagers, a researcher at the Harvard Stem Cell Institute, who is a coauthor on two of the three new works. Last year, Wagers had reported that linking the circulatory systems of an older mouse and a younger mouse at the hip helped improve the appearance and function of the weakened, enlarged hearts of older mice. The team then screened the blood of young and old mice to look for differences and found that older mice had less of a protein growth factor called GDF11, which is also found in human blood.
[232 words]

[Time 4]
Wagers and team then found that an injection of the protein into old mice had similar beneficial effects on the heart. In a new study published in the journal Science, Wagers and team show that it also has restorative effects on muscles in mice. In a second report, Wagers and her colleagues showed that the protein has restorative effects on the brains of older mice.  

“The most exciting aspect of the set of papers is that there is a common signal talking to the brain, heart, and skeletal muscles,” says Wagers. “The same signal is talking to at least three organs and multiple cells types within each organ.”

A separate recent study from scientists at Stanford University showed that young blood changes older mice’s behavior and neural circuitry. The team saw improvements in learning and memory and a strengthening of connections between neurons in the hippocampus, a structure important to memory that deteriorates with age, even more so with diseases such as Alzheimer’s. The West Coast group, unlike the Harvard group, did not identify a specific protein responsible for the effects.

Based on Wagers’s new and previous results, the Boston-area venture capital firm Atlas Venture has started a still-unnamed company. Wagers’s previous findings caught the eye of the VC firm in 2013, and the new results “increased the excitement for the role of GDF11 in aging,” says partner Peter Barrett. “Now it’s the blocking and tackling of trying to understand what would be the best therapeutic approach to make this a commercial product.”
[254 words]

[Time 5]
The company might target heart failure first, since Wagers’s team has shown that the growth factor can reverse age-related thickening of heart muscle in mice. In human patients, such thickening of the heart tissue can cause heart failure, and the condition currently has no treatment options, says Wagers.

GDF11 alone does not provide the full beneficial effects of young blood, says Wagers. “But now that we have a molecule that we can understand at a mechanistic level, we can start to build out the network of what is changing in the blood, find things that interact with GDF11, and regulate it to give us a clearer view of the network,” she says.

Though the results are exciting, there are many outstanding questions, including potential side effects. Other such growth factors, which encourage cell division, have been linked to cancer. Furthermore, blood vessel growth is a common feature of cancer development, and genes involved in stem cell function and regeneration have been linked to tumor growth. The Harvard-based studies on heart muscle, skeletal muscle, and brains were all conducted on the same mice, and the longest that the researchers studied the treated mice was 60 days. No ill effects were detected in those time frames, says Wagers.

One of the Stanford researchers, Tony Wyss-Coray, has cofounded a biotech company called Alkahest to test the therapeutic potential of his group’s findings.
[229 words]

Source: MIT Technology Review
http://www.technologyreview.com/news/527146/can-compounds-in-young-blood-fix-aging/


Blood poisoning increases the risk of blood clots, new research shows
Date:March 14, 2014
Source:Aarhus University

[Time 6]
"We have followed more than 4,000 people who have been admitted with blood poisoning. The study shows that the risk of suffering a blood clot in either the brain or the heart is twice as high for patients with blood poisoning in relation to other patients who are also admitted with acute illnesses," says Michael Dalager-Pedersen , PhD student at Aarhus University and Registrar at Aalborg University Hospital. He has carried out the study in collaboration with colleagues from Aarhus University, Aarhus University Hospital, and Aalborg University Hospital.

The risk of a blood clot was highest within the first 30 days after the infection, where the risk was 3.6 percent against 1.7 percent for the other acutely admitted patients, and only 0.2 percent among the population in general.

The study has just been published in Circulation.

In recent years there has been a growing level of interest for the correlation between the risk of blood clots and infections such as blood poisoning. The researchers hope that the new knowledge can be utilized to ensure better prevention and earlier treatment. "It is important that we have now documented that there is a clear correlation between blood poisoning and blood clots. The new knowledge can be used by the medical doctors to increase focus on this patient group so they can begin relevant treatment quicker," says Reimar Wernich Thomsen from the Department of Clinical Epidemiology at Aarhus University and Aarhus University Hospital.

He explains that the correlation may, among other things, be due to the fact that the blood clots arise due to the increased strain on the heart and blood vessels that the infection causes.
[274 words]

Source: Science Daily
http://www.sciencedaily.com/releases/2014/03/140314111527.htm

Cassidy大洁洁

Part III: Obstacle

Your Blood Type is a Lot More Complicated Than You Think
By Daniel A. Gross | June 5, 2014

[Paraphrase 7]
Not long ago, a precious packet of blood traveled more than 7,000 miles by special courier, from America to Australia, to save the life of a newborn. Months before the delivery date, a routine checkup of the mom-to-be had revealed that the fetus suffered from hemolytic disease. Doctors knew that the baby would need a blood transfusion immediately after delivery. The problem was, the baby's blood type was so rare that there wasn't a single compatible donor in all of Australia.

A request for compatible blood was sent first to England, where a global database search identified a potential donor in the United States. From there, the request was forwarded to the American Rare Donor Program, directed by Sandra Nance. The ARDP had compatible frozen blood on hand, but Nance knew that a frozen bag might rupture in transit. So her organization reached out to the compatible donor, collected half a liter of fresh blood, and shipped it across the Pacific. When the mother came in to give birth, the blood was waiting. “It was just magic,” Nance says.

You’re probably aware of eight basic blood types: A, AB, B and O, each of which can be “positive” or “negative.” They're the most important, because a patient who receives ABO +/– incompatible blood very often experiences a dangerous immune reaction. For the sake of simplicity, these are the types that organizations like the Red Cross usually talk about. But this system turns out to be a big oversimplification. Each of these eight types of blood can be subdivided into many distinct varieties. There are millions in all, each classified according to the little markers called antigens that coat the surface of red blood cells.

AB blood contains A and B antigens, while O blood doesn't contain either; “positive” blood contains the Rhesus D antigen, while “negative” blood lacks it. Patients shouldn’t receive antigens that their own blood lacks—otherwise their immune system may recognize the blood as foreign and develop antibodies to attack it. That’s why medical professionals pay attention to blood types in the first place, and why compatible blood was so important for the baby in Australia. There are in fact hundreds of antigens that fall into 33 recognized antigen systems, many of which can cause dangerous reactions during transfusion. One person's blood can contain a long list of antigens, which means that a fully specified blood type has to be written out antigen by antigen—for example, O, r”r”, K:–1, Jk(b-). Try fitting that into that little space on your Red Cross card.

Scientists have been discovering unexpected antigens ever since 1939, when two New York doctors transfused type O blood into a young woman at Bellevue Hospital. Type O was considered a “universal” blood type that anyone could receive, yet the woman experienced chills and body pain—clear signs that she was reacting to the blood. After running some lab tests, the doctors confirmed that even type O blood could contain previously unknown antigens. They’d accidentally discovered Rhesus antigens.

Additional kinds of antigens have been discovered every few years since then. Almost everyone has some. More than 99.9 percent of people carry the antigen Vel, for example. For every 2,500 people, there's one who lacks the Vel antigen who shouldn't receive blood from the remaining 2,499. (Like many blood types, Vel-negative is tightly linked to ethnicity, so how rare it is depends on what part of the world you’re in.) If a Vel-negative patient develops antibodies to Vel-positive blood, the immune system will attack the incoming cells, which then disintegrate inside the body. For a patient, the effects of such reactions range from mild pain to fever, shock and, in the worst cases, death.

Blood types are considered rare if fewer than 1 in 1,000 people have them. One of the rarest in existence is Rh-null blood, which lack any antigens in the Rh system. “There are nine active donors in the whole community of rare blood donors. Nine.” That's in the entire world. If your blood is Rh-null, there are probably more people who share your name than your blood type. And if you receive blood that contains Rh antigens, your immune system may attack those cells. In all, around 20 antigen systems have the potential to cause transfusion reactions.

Just to be clear, transfusion patients today don't have much to worry about. In 2012, there were tens of millions of transfusions in the United States, but only a few dozen transfusion-related deaths were reported to the U.S. Food and Drug Administration. Medical practitioners go to great lengths to make sure that transfused blood is compatible. But curiously enough, they manage to do this without even knowing all the antigens present.

Before a transfusion takes place, lab technicians mix a sample of the patient's blood with the sample of a donor whose blood type is ABO +/– compatible. If the two samples clump, the blood may be unsafe to transfuse. “The moment you discover that, you do not know why,” Nance explains. Figuring out the precise cause of the problem is like solving a crossword puzzle, she says. “You test many donors that are known types, and you find out, just by process of elimination, what is the contributing factor that makes this incompatible.”

This was the process that helped the newborn in Australia. Lab technicians there had tested the fetal blood and figured out which antigens they needed to avoid. But they still didn't know where in the world they might find suitable blood. So they sent a rare blood request to the international organization set up for cases just like this: the International Blood Group Reference Laboratory in Bristol, England. The IBGRL consults its database of hundreds of thousands of rare donors worldwide to find compatible blood. For the past 30 years, the process of global blood sharing has been gradually standardized during the biennial congress of the International Society for Blood Transfusion, which took place this week in Seoul, South Korea.
[1000 words]

[Rest]
In the past two years, at least 241 packets of rare blood were shipped internationally, according to Nicole Thornton, head of Red Cell Reference at the IBGRL. Many more are shipped within national borders. In 2011, for example, more than 2,000 units of rare blood were shipped within the United States. It’s an impressive feat of coordination.

Even rare donor programs with the resources to identify and ship rare blood are looking to improve. There just aren't enough rare donors who come in regularly. The American Rare Donor Program has 45,000 rare donors in its database, but 5 percent of transfusion patients still don't get the blood they need. Coral Olsen, a scientist in charge of regional rare blood banking in South Africa, says that her laboratory often struggles to keep track of registered rare donors. “Because a lot of them are from rural settings, we often can't get ahold of them. So that's our challenge, as far as tracing and tracking and maintaining our rare donor base.”

For many countries, an even bigger challenge is simply dealing with resource constraints. National blood laboratories have to maintain a repository of samples if they want to run detailed antigen tests. Olsen says that in developing countries, where starting samples aren’t always available, it's difficult to even begin classifying and sourcing rare blood. Finally, there's the high cost of importing rare types, especially for patients who need chronic transfusions. In those cases, medical professionals sometimes have to use blood that's known to be incompatible, but unlikely to cause severe reactions because of the particular antigens involved.

One day, scientific breakthroughs may make it easier to find compatible blood for anyone. Geneticists are working on testing methods that determine blood types using DNA, without looking at the blood itself. (So far, this process only works with certain antigens.) Nance hopes that one day, every newborn will undergo testing so that blood banks can build a comprehensive database of every rare type, which would immediately point medical professionals to the nearest compatible donor. Biochemists, meanwhile, have been testing chemicals that effectively mask the antigens on red blood cells, seeking to turn them into “stealth” cells that are functionally universal.

Until then, researchers will probably go on discovering antigens one by one. It's as if the surface of red blood cells started out as a fuzzy picture that scientists have slowly brought into focus, revealing subtle differences that just weren't visible before. For blood scientists and patients with rare blood types, these differences can be tedious and troublesome. But they're also a reminder of our remarkable individuality. With hundreds of possible antigens and millions of possible antigen combinations, your blood can be as unique as your fingerprint.
[452 words]

Source: Smithsonian
http://www.smithsonianmag.com/science-nature/your-blood-type-lot-more-complicated-you-think-180951669/

zp1107

2.10
1.55
2.01
1.50
2.03
7.07
The blood type is much more than well known 8 basic types, the story about the rare blood type of the baby shows how rare of the type. It also explains the history how the rare types are found. Transfusion nowadays are standardized and safe.

Olivia的monde

T2 1'22'85
T3 1'29'40
T4 1'19'97
T5 1'30'92
T6 1'18'60
Obstacle:10'48'44
1.start:a newborn baby needs compatible blood ARDP
2.introduction of blood:types of blood:ABO +/–,compatible blood is important, unexpected antigens,addition kind antigens,rare blood types RH-null.
3.transfusion patients today don't have much to worry about, lab technicians mix a sample to test safe or not.
4.IBGRL offer the help: shipped internationally,but 5% transfusion don't get blood
5. in some countries: bigger challenge is simply dealing with resource constraints.(developping countries)
6. scientific breakthroughs may make it easier to find compatible blood for anyone.geneticists.
7.future: antigens-makes it unique,a reminder of your individuality

TVXQashley

time 2  1:19
time 3  1:30
time 4  1:41
time 5  1:14
time 6  1:28

obstacle  6:20

14/10/21

samantha12

Reading 2 1:20.19
A professor promoted a result based on a research, which has 3 experimental groups and led to a useful result.

Reading 3 1:29.00
A surprising experimental result has been published, with an impressive hypothesis. The cause for this result has been claimed, according to a experiment.

Reading 4 1:37.17
Further instruction about W' s impressive experiment has been stated. Because of the surprising result, people start to apply this scientific outcome to commercial usage.

Reading 5 1:35.13
When the result has been applied into practical usage, we should first concerned about the heart failure. Even though the special molecule they've found cannot function on its own, as well as some outstanding side effects have been demonstrated, there's someone definitely willing to solve these problems.

Reading 6 1:47.57
In this part, we find out a further concentration on blood clot.  And its general introduction has been confirmed.

Obstacle 10:31.51
At the beginning, an special helping case has been introduced, at this time we first know the organization located in England.
Then the article started to give us some information about the blood type and antigens, which cause the incompatible reflection among bloods.
After that, we've been noticed that a severe result could happen because of this incompatible result. And how to definite a rare blood type. If one born with this rare type of blood is ill, what we should do? Then we returned to the case that have been introduced above.
With the organization's help, some problems could be solved. However, the organization itself suffers a kind of questions. The first concerns about the way we get rare blood type, a series of work has been done but not enough; the second, the most critical, concerns about the blood transportation, which could determine a human's live.

cherry6891

43-10
Time2
Having high blood pressure(hypertension) at any point in trail will increase the risk of stroke for atrial fibrillation patients
Time3
The blood of young mice rejuvenate the old mice. A single protein found in the blood is sufficient to restore muscle and improve brain activity.
Time4
An injection of protein to old mice had similar beneficial effect on heart. Plus a separate study by Stanford university found that young blood changes the old mice behavior and neural circuitry. W team is trying to develop commercial use.
Time5
The company may targeted heart failure first since the growth factor can reverse age-related thicking of muscle.
However,the protein can not make all the beneficial of young blood.
Time6
The study shows that the risk of suffering blood clot for patients is twice as high as patients with blood poisoning.
The correlation between the blood clot and blood poison get a lot of interest

Obstacle
Article starts with a story of baby in Australia who need a rare type of blood and finally the baby got compatible blood. Then author introduces the types of blood and the antigens the blood carry. Besides that,the principle the doctor need to follow during transfusion. Every blood is as unique as fingerprint,hopefully the database of blood complete soon.

seraph797979

Cassidy大洁洁 发表于 2014-10-21 20:30
Part II: Speed

High blood pressure increases risk of stroke for atrial fibrillation pat ...

2,1‘25
3,1’18
4,1‘24
5,1’33
6,1‘16

AgendaChen

Speaker
Anticlotting substance can be used to treat patients, but it also causes deadly bleeding. Recently, researchers test a coating of carnivorous plant and find that such coating can make blood keep flowing without clotting for eight hours, compared to an hour in normal condition.

time2
A finding shows that if people with atrial fibrillation have a high blood pressure, they will be 50% more likely than those who don't have to have stroke.
1m23

time2+3+4
A recent experiment shows that blood of young mice is helpful for old mice's musscle, heart, and brain. The researcher find a protein named GDF11 that may be the key to this phenomenon by comparing the young blood and old blood. What's more, there are many previous studies also showing that young blood can improve the behaviour of old mice.
The finding is so exciting that it catch the eye of the VC firm. However, there are still many outstanding questions. For example, the side effect of such treatment is unknown and risky.
4m3s

time6
A study involing more than 4000people shows that people with blood poisoning will be more likely to suffer a blood clot. Researchers believe that this knowledge will be helpful for medical doctors to treat their patients in this group.
1m41s

Ob
In order to save a newborn suffered from hemolytic disease in Australia, doctors send rare blood requestion to England and the United States to find a compatible donor. Finally, they successfully find such person in the United States and ship a liter of fresh blood from this person to Australia to save the baby.

With this magic event, the author begins to introduce the knowledge of our complicated blood type. For example, the rarest type of blood is Rh-null blood.

Even though blood type is so complicated, we don't have to worry that we can't find a compatible type when we need external blood because although doctors don't know all types of blood, they can figure out which type is compatible by mixing a sample of the patient's blood with the sample of a donor. For example, if the two sample clump, the type of this donor is not safe to transfuse. So, the doctors can find the most suitable type by the process of elimination.

However, there are still some problems for tranfusion. The first one is that most rare donors are in rural settings and thus it is hard for doctors to track and keep contact with them. The second one is that in some developing countries, it's difficult to classfy and reserve rare blood.

In the end, the author hopes that one day, all these problems will be fixed and that no one needs to worry blood transfusion.
9m45s