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  • 2021-1-29 葡萄牙的冠病疫情严重,医疗系统濒临崩溃。国会28日批准延长封城至下月中,并于29日起封锁接壤西班牙的边境两周

    葡萄牙的冠病疫情严重,医疗系统濒临崩溃。

    国会28日批准延长封城至下月中,并于29日起封锁接壤西班牙的边境两周。

    总理科斯塔形容国内疫情恐怖,承认可能是去年圣诞及年末放宽防疫所导致的。

    葡萄牙于本月15日起封城,有限期现时再延长至下月14日,暂停所有非必要服务,非必要商店及设施关闭,酒吧及餐厅只可提供外卖,社交活动只限同一家庭人员,强制所有工人在可行情况下在家工作,所有学校关闭。惟该国在本星期日如常举行总统选举。

    科斯塔指出,国内疫情不是差,而是恐怖,未来数周将面对最差的情况,指出疫情在政府去年底放宽防疫后转差,

    另一个原因是有新变种新冠病毒传入。他又承认自己传递讯息不清,令国民误会,是他的错误。

    德国会派军方医疗专家到葡萄牙研究援助方案,但科斯特指出葡萄牙要求的物资,德国大多无法提供,包括医护人员。

  • 30 Jan, 2021 MIT’s Rudolf Jaenisch found that the coronavirus may be able to insert its genes into human DNA, but says there is no evidence that mRNA vaccines do the same.He says the findings should not be used to support anti-vax arguments and says that even if they are found to affect human genes it would be a good thing

    A leading biologist whose team recently discovered that the coronavirus that causes Covid-19 may be able to insert its genes into human DNA has said there is no cause for alarm over vaccines that mimic the process of infection.
    The discovery by Professor Rudolf Jaenisch and researchers at the Massachusetts Institute of Technology, stirs up a hornet’s nest because mRNA vaccines, including those made by Pfizer/ BioNTech and Moderna, operate in similar ways to the virus to trigger an immune response.
    But he said there is “absolutely no evidence” that these vaccines would alter human DNA.
    Jaenisch, a pioneer in the field of transgenics, added that if they are found to do so it may actually be a good thing, saying: “One could speculate that such an integration, if indeed happening, might result in more long-term expression of the antigen [a substance that causes the immune system to create antibodies] and thus be beneficial.”

    Though some researchers said the finding was unexpected and could fundamentally change our understanding of the virus, Jaenisch said it should not be used as an argument against vaccination.
    The mRNA vaccines only use parts of the virus’ genes known as messenger RNA, not the whole sequence. Because these gene segments do not include components that are important for viral functions, adverse effects such as triggering unwanted mutations should be minimal.
    Jaenisch however admitted that “at this point we just do not have much information” on certain questions concerning the safety of mRNA vaccines, such as whether more research should be conducted before the mass vaccination of entire nations.

    Jaenisch’s caution reflects a dilemma in the research community when using new technology to battle a new virus. Before the pandemic, and despite decades of efforts, no mRNA vaccines had completed clinical trials but now the Pfizer/BioNTech and Moderna vaccines have completed the process.
    The current large-scale vaccination programmes in many countries have so far only received authorisation for emergency use.
    The risk that an mRNA vaccine will change human DNA and cause unexpected diseases is small compared with the catastrophic damage caused by the ongoing pandemic, but there are concerns in the health care community about the technology’s safety and potential side effects, especially in the long run.
    In a survey of nearly 1,000 health workers (mostly doctors) in Hong Kong last week, only 22 per cent said they would use the Pfizer/BioNTech jab, with the majority preferring vaccines made using more traditional methods.
    The MIT study, which has not yet been peer-reviewed, received enormous attention in the global research community.
    Nobel Prize winner David Baltimore told Science magazine the results were “impressive”. The coronavirus was thought to be harmless to human DNA, because its genes were unable to enter the cell nucleus, where the DNA was kept.
    Some researchers have asked Jaenisch to retract the paper because it could affect people’s confidence in the new vaccines.
    “This preprint has already attracted the attention of the anti-vaccine crowd,” said a commentator on biorxiv.org, where the study was posted.

    Some questioned the validity of their findings. The discovery was made in a Petri dish, and what really happens in the human body could be quite different, according to some critics.
    The mRNA vaccines are by far the most powerful and effective weapon against the coronavirus, promising an efficacy rate of more than 90 per cent.
    The vaccines can deliver viral genes into many kinds of human cells and turn them into a factory producing the virus’s spike protein. Our immune system then remembers these unique proteins and stages a swift, precise response when it encounters the real virus.
    But if the viral genes carried by the mRNA vaccine could get into the nucleus through the previously unknown mechanism described by the new study, there is a chance that it could alter our DNA and cause unexpected mutations.

  • 2021年1月30日 巴西研究人员发现那两名同时感染两变种冠病病毒的患者均为30多岁,症状轻微,不需要住院治疗,但这两起个案凸显了可能有多个变种病毒正在巴西传播。科学家更担忧两个变种病毒共存可能加速病毒突变。

    (巴西利亚综合电)南美洲国家巴西的研究人员发现有两名患者同时感染了两个变种的冠状病毒,这是全球首个证实两个毒株同时出现在患者体内的个案。

    巴西南部的研究人员所发现的这两名患者均为30多岁,症状轻微,不需要住院治疗。这两起个案凸显了可能有多个变种冠病病毒正在巴西传播。科学家更担忧的是,两个变种病毒共存可能加速病毒突变。

    这项研究的首席研究员、费维尔大学的病毒学家费尔南多·斯皮尔基说:“这些同时感染两个病毒的情况可能引致病毒组合,令病毒以比我们所知的速度,更快产生变异体。”

    新的变体带来更大的传播风险,并可能对目前正在开发的疫苗产生耐药性。

    在英国以及在巴西亚马逊州发现的变种冠状病毒似乎更具传染力。

    斯皮尔基说,这些病例表明,目前有大量的不同病毒在巴西传播,因为,只有在这种情况下,才会出现患者同时感染两个病毒的病例。

  • 2021-1-28 美国诺瓦瓦克斯医药公司(Novavax)1月28日表示,在英国进行关键第3阶段临床试验中,这款需打两剂的疫苗对原始冠状病毒的效力为95.6%,但对南非变种病毒效力减半。

    据法新社发自华盛顿的报道,诺瓦瓦克斯疫苗在英国的试验涵盖1万5000名18岁至84 岁的受试者,其中27%的受试者,年龄超过65岁。

    研究显示,这款疫苗对于原始冠状病毒(Covid-19)的防护力高达95.6%,对于英国变种病毒为85.6%,但在一个规模较小、仅4千400多人的试验中,这款疫苗对南非变种病毒的防护力则降到49.4%。

    诺瓦瓦克斯公司表示,已于本月初着手因应新病毒株的新款疫苗,预计未来几天就会选出理想的候选疫苗,接着在第2季展开临床试验。

    诺瓦瓦克斯新病毒NVX-CoV2373疫苗是美国政府疫苗研发计划“快速行动”(Operation Warp Speed)的6支候选疫苗之一,获得17.5亿美元的经费资助,同时也在美国和墨西哥进行临床试验。

    法新社这个报道说,美国辉瑞(Pfizer)和莫德纳(Moderna)生产的mRNA疫苗,是将新冠病毒棘状蛋白的“核糖核酸信使”(mRNA)送至体内,产生抗病毒的蛋白保护人体。而诺瓦瓦克斯疫苗则是注射病毒的蛋白进入人体,刺激人体产生抗体。

  • 2021-1-29 新冠感染者的嗅觉倒错

    许多Covid-19患者暂时失去了嗅觉。当他们病好后,嗅觉通常会恢复,但有些人会发现东西闻起来不一样了。本来应该闻起来不错的东西,如食物、肥皂和他们的爱人,闻起来却让人反感。

    这种被称为嗅觉倒错(parosmia)的疾病患者数量在不断增长,但科学家们不确定为什么会发生这种情况,也不知道如何治愈这种疾病。

    克莱尔的医生说他以前从未遇到过这种情况。克莱尔害怕又困惑,于是在网上寻找答案,并在脸书上找到了一个由嗅觉缺失慈善机构“AbScent”成立的群组,群组有6000名成员。

    几乎所有人都是因为新冠病毒导致嗅觉丧失,最后都引发了嗅觉倒错。“对不同气味的常见描述包括:死亡、腐烂、腐烂的肉、粪便,”AbScent创始人凯利(Chrissi Kelly)说。

    她称新冠病毒嗅觉倒错病例频出后,于6月创建了这个脸书群组。

    约65%的新冠病毒感染者失去了嗅觉和味觉,据估计,其中约10%会发展为“嗅觉定性障碍”,即嗅觉倒错或更罕见的疾病:幻嗅症。

    如果数字正确,那么全球1亿新冠病毒感染者中,多达650万人现在可能正患有嗅觉倒错。

    有一种说法认为,患有这种疾病的人闻到可怕气味是因为,他们只感知到物质所包含的一些挥发性化合物,孤立地闻起来更难闻,它们的强度甚至可以提高。

    例如,咖啡中含有硫化物,这些化合物和其他分子结合在一起闻起来很香,但单独闻起来就不太好了。

    英国雷丁大学科学家帕克(Jane Parker)和AbScent脸书群组的一些人合作发现,肉、洋葱、大蒜和巧克力,以及咖啡、蔬菜、水果、自来水和葡萄酒通常会引起不良反应。

    对一些志愿者来说,大多数其他东西都是不好闻的,没有什么东西对他们来说是好闻的,“也许除了杏仁和樱桃”。

    帕克说,志愿者们和其他嗅觉倒错患者反复描述几种难闻的气味,一种是化学和烟熏味,一种是甜味和令人作呕的气味,还有一种“呕吐物气味”。

    她的研究还发现,难闻的气味可能会在患有嗅觉倒错的患者身上停留超乎寻常地久。对大多数人来说,咖啡的香味只会在鼻孔里停留几秒钟。对于嗅觉倒错患者,它可以停留几个小时,甚至几天。

    全球化学感官研究协会英国负责人史密斯(Barry Smith)教授说,另一个惊人发现是,对于一些人来说,尿布和卫生巾的气味变得令人愉悦,“就如同,人类排泄物闻起来像食物,而食物现在闻起来像人类排泄物。”

    什么导致了嗅觉倒错?普遍的假设是,它是因为神经纤维受损造成的。

    神经纤维将信号从鼻子的感受器传递到大脑中嗅球的末端。帕克说,当这些纤维重新生长时——无论损伤是由车祸造成的损伤,还是由病毒或细菌感染引起的——人们认为这些纤维可能会重新连接到错误的末端。

    “他们进错会议室了!这被称为‘交叉布线’,这意味着大脑无法识别这种气味,而且可能被认定为是危险的。”

    理论上,在大多数情况下,随着时间推移大脑会纠正这个问题,但是帕克不愿透露需要多长时间。

    “因为很少有人在新冠疫情之前患有嗅觉倒错,对它的研究不多,大多数人都不知道它是什么,所以我们没有历史数据。我们没有针对新冠病毒的数据,因为这可能需要数年时间,”她说。

    除了等待大脑适应,没有治疗方法,但AbScent认为“嗅觉训练”可能有帮助,这包括定期闻一批精油。还有患者调整了饮食应对。