中山拉血病因(中山看混合痔哪家好) (今日更新中)

WASHINGTON, Aug. 4 (Xinhua) -- Observations from NASA's Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars, the U.S. National Aeronautics and Space Administration (NASA) announced Thursday.Dark, finger-like features appear and extend down some Martian slopes during late spring through summer, fade in winter, and return during the next spring. Repeated observations have tracked the seasonal changes in these recurring features on several steep slopes in the middle latitudes of Mars' southern hemisphere."The best explanation for these observations so far is the flow of briny water," said Alfred McEwen of the University of Arizona, Tucson.McEwen is the principal investigator for the orbiter's High Resolution Imaging Science Experiment and lead author of a report about the recurring flows to be published in Friday's edition of the journal Science.Seven such sites on the planet have been confirmed, with 20 more possible, McEwen said."What makes these new observations so interesting is they occur at much lower latitudes where temperatures are much warmer and where it's actually possible for liquid water to exist," said Arizona State University geophysicist Phil Christensen, one of the scientists who studied the images beamed back from the orbiter.The study does not prove water exists, but identifies it as the best explanation. It's worthwhile to think about alternative reasons for these observations, but none seems to fit as well as briny water, McEwen said."I think it's going to be laboratory experiments on Earth that give us the best confirmation or refutation," he said.

SAN FRANCISCO, Aug. 23 (Xinhua) -- The amount of malware targeted at devices based on Google's Android platform surged 76 percent in the second quarter over the previous three months in 2011, making it the most attacked mobile operating system, computer security firm McAfee said on Tuesday.A new McAfee study found that in the second quarter, Android- based malware surpassed Nokia's Symbian as the most popular target for mobile malware developers.While Symbian and Java ME, a platform designed for mobile devices and other embedded systems, remain the most targeted to date, the rapid rise in Android malware indicates that the platform could become an increasing target for cyber criminals McAfee said.Models pose with the new Samsung Galaxy S Android smartphone during its launch ceremony at the headquarters of Samsung Electronics in Seoul in this June 8, 2010 file photograph.It warned that the attacks on Android platform could affect everything from calendar apps, to text messages, and even a fake Angry Birds updates.According to the study, malware on mobile platforms is increasing steadily, often mimicking the same code as personal computer-based threats, as vast amount of personal and business data are now found on user's smartphones and other mobile devices."This year we've seen record-breaking numbers of malware, especially on mobile devices, where the uptick is in direct correlation to popularity," Vincent Weafer, senior vice president of McAfee Labs, said in a statement."Overall attacks are becoming more stealth and more sophisticated, suggesting that we could see attacks that remain unnoticed for longer periods of time," he noted.

LOS ANGELES, July 18 (Xinhua) -- At least 70 genetic mutations may be involved in the formation of colon cancer, far more than scientists previously thought, a new study suggests.The study by researchers at University of Texas (UT) Southwestern Medical Center contradicts previous thinking that only a few mutated genes may play a role in the development of colon cancer."The ways we've been treating patients up to now is to just go after one target when we should be going after three to four different pathways simultaneously," said Dr. Jerry W. Shay, vice chairman and professor of cell biology at UT Southwestern.The new study identified 65 candidate genes and at least five passenger genes whose mutations play significant roles in cancer development. Inactivating the function of any of these tumor- suppressing genes led to a key step in cancer development called anchorage-independent growth, meaning cells piled up on top of each other rather than aligning neatly.According to previous studies, there were 151 candidate genes and that mutations in just eight to 15 of them would lead to cancer. There were 700 other genes classified as passenger genes whose mutations were incidental to cancer growth.Current cancer treatments target just one or two known cancer- driver genes. While patients may get transient tumor burden reduction, almost universally tumor growth returns."Those numbers are dead wrong," Dr. Shay said, suggesting a new approach to colon cancer treatments targeting multiple genes and pathways simultaneously.The next step is further research to classify more accurately which genes drive cancer and which are merely passengers, the researchers said.Study findings were published in the July 2011 Cancer Research (Priority Reports).

LOS ANGELES, June 5 (Xinhua) -- U.S. researchers have developed two new drugs that can prolong the lives of patients with advanced melanoma, it was announced on Sunday.Research on both drugs was presented at the on-going annual meeting of the American Society of Clinical Oncology in Chicago, according to HealthDay News.This is the first big news in years for treatment of melanoma, one of the deadliest forms of skin cancer and one that is notoriously difficult to treat, let alone cure, the report said.The first treatment, vemurafenib, inhibits a gene mutation harbored in half of all melanoma patients, but is not yet approved by the U.S. Food and Drug Administration.The other drug, Yervoy (ipilumumab), is an immune system therapy that won approval in March."The March FDA approval of ipilumumab (Yervoy) was the first new drug approval for melanoma in 13 years," said Tim Turnham, executive director of the Melanoma Research Foundation.The two drugs were developed by researchers at Memorial Sloan- Kettering Cancer Center in New York City, the report said."This is really a huge step toward personalized care in melanoma," Dr. Paul Chapman, lead author of the first study and the attending physician in the melanoma/sarcoma service at Memorial Sloan-Kettering, said in a statement. "This (vemurafenib) is the first successful melanoma treatment tailored to patients who carry a specific gene mutation in their tumor, and could eventually become one of only two drugs available that improves overall survival in advanced cancers.""Having two trials that show a benefit in survival in patients with melanoma, both of these in first-line settings -- we weren't here just a few years ago," said Dr. Stephen Hodi, director of the Melanoma Center at Dana Farber Cancer Institute in Boston. "These are huge, paradigm-shifting results for the field."In the vemurafenib trial, sponsored by the drug's makers, researchers randomly assigned 675 patients with advanced, inoperable melanoma to receive either the chemotherapy drug dacarbazine or vemurafenib. Vemurafenib targets the V600E mutation in the BRAF gene.At the three-month mark, patients taking vemurafenib were 63 percent less likely to die and 74 percent less likely to die or see their cancer return, compared to patients taking dacarbazine alone.Few patients had side effects in the vemurafenib group, although some did develop squamous cell carcinoma, a less dangerous form of skin cancer.This is the first drug that has been proven superior to chemotherapy in this group of hard-to-treat patients, the researchers said."There was such a substantial benefit that we recommended that patients cross over," Chapman said at a Sunday news briefing. "It' s unprecedented to report a trial this early. The median follow-up time was three months." Yet the differences between the two groups became evident almost immediately.Dr. Lynn Schuchter, co-moderator of the briefing and division chief of hematology-oncology at Abramson Cancer Center of the University of Pennsylvania in Philadelphia, said symptoms subsided in some patients almost immediately, enabling them to cut back on pain medication in just 72 hours."The median time to progression with dacarbazine was 1.6 months versus three months with vemurafenib, which is a huge difference," said Chapman.In the second study, about 500 patients were randomly picked to receive Yervoy plus dacarbazine or dacarbazine alone.Those taking both drugs lived a median of 11.2 months compared to 9.1 months for those taking dacarbazine alone. Time to recurrence of disease was about the same for both groups: 2.8 months and 2.6 months, respectively.Almost half of those taking the combination therapy were alive after one year, compared to 36.3 percent in the other group. After two years, the rates were 28.5 percent and 17.9 percent, respectively.By three years out, 20.8 percent of those in the combination group were alive compared with 12.2 percent of those taking chemotherapy alone.This is the first study to combine chemotherapy and immunotherapy both safely and effectively.A study to test vemurafenib in combination with Yervoy has already begun, according to HealthDay News.

CANBERRA, Aug. 3 (Xinhua) -- As many as a quarter of Australian women have experienced some form of assault or sexual abuse, and the higher proportion of the abuse, the higher rates of metal illness a woman tends to suffer from, a new study released on Wednesday found.Researchers from the University of Melbourne and the University of New South Wales conducted the study survey of 4451 Australian women aged 16 to 85. It looked at their experience of the four most common types of gender-based violence - sexual assault, rape, stalking and being badly beaten by their partners.About 15 percent of Australian women report sexual assault, while eight percent report rape, 10 percent said they have a stalker and eight percent report being beaten by their partner.It found strong links between those four types of violence and mental health problems including attempted suicide, posttraumatic stress disorder, panic attacks, depression, anxiety, and substance abuse.Among the women who experienced at least one form of violence, 30 percent had a mood disorder, nearly 40 percent an anxiety disorder, 23 percent were abusing substances and 15 percent were affected by posttraumatic stress syndrome.For the women who suffered higher levels of violence, the rates of anxiety disorders was 77 percent, 52 percent for mood disorders, substance abuse 47 percent and posttraumatic stress syndrome 56 percent.More than six percent of women experienced one form of violent had attempted suicide, compared to 35 percent of women who suffered at least three forms of violence.Public health expert Dr Susan Rees from the University of New South Wales' school of psychiatry, who led the research, said she is especially concerned about the suicide rate of women who are abused."What we found was that there's a high association or a strong association between exposure to gender-based violence and all the three broad classes of mental disorder - so that includes mood, anxiety, substance abuse - and a very high association with attempted suicide," she said in the report released on Wednesday."Women who've not experienced gender-based violence have about a 1.6 percent rate of attempted suicide and that increased to six percent of women who had experienced one type of gender-based violence."She said that gender-based violence was also associated with physical disability, impaired quality of life and a worsening of any existing mental disorders.Dr Rees called for the health care system, particularly psychiatric services, to work closer with women's services to improve support for victims of violence.She added that the federal government also need to underscore the importance of getting to the root cause of the violence against women by looking at attitudes towards women and gender inequality.The study was published in the Journal of the American Medical Association.

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