Showing posts with label #coronavirususa. Show all posts
Showing posts with label #coronavirususa. Show all posts

Tuesday, March 31, 2020

What Is a Virus? #Covid19Virus, #CoronaVirustips, #Covid19nz, #lnzlockdown

What Is a Virus?
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A computer illustration of coronavirus particles.
A virus is genetic material contained within an organic particle that invades living cells and uses their host's metabolic processes to produce a new generation of viral particles.


The way they do this varies. Some insert their genetic material into the host's DNA, where it can sit in wait until it's translated at a later date. As the host cell replicates itself, it can make new viruses.

Viruses can also burst their host cell as they expand in numbers, in what's called a lytic cycle of reproduction.

How big are viruses?
The word virus comes from a Latin word describing poisonous liquids. This is because early forms of isolating and imaging microbes couldn't capture such tiny particles.

Virus sizes vary from the extremely minuscule - 17 nanometre wide Porcine Circovirus, for example - to monsters that challenge the very definition of 'virus', such as the 2.3 micrometre Tupanvirus.

Similarly, they come in a range of complexities, containing different proteins or surrounded by an array of shells and envelopes to assist in their infection and reproduction of just about every species across every kingdom of life.

Viruses can be encoded in a variety of ways. Rotaviruses are based on a double strand of RNA, for example. Coronaviruses have a single strand of RNA, which is 'positive sense', as in it can be translated directly into new proteins. Influenza has negative sense RNA, meaning it needs an extra transcribing step before it can make proteins.

Smallpox and herpes viruses are examples of DNA viruses, which force the host to transcribe its genome into RNA on entry.

Sizes of these genomes also vary. Some of the largest can be over a million base pairs long. On the other hand, an RNA virus that infects bacteria, called MS2, has barely 3,500 base pairs.



It's impossible to know with certainty just how many types of viruses exist in the natural world, with numbers climbing as researchers use new tools to search for classified and unknown genetic signatures in the soil, oceans, and even the skies. Rough estimates suggest there could be as many as 100 million types of virus on Earth's surface.



Are viruses alive?
This is a question scientists continue to discuss as definitions of life and ecology change. Current thinking suggests viruses should be considered part of a complex living system, one that extends between all organisms.

'Virions' are the inactive particles that move through the environment, which we don't tend to think of as alive. Only once they're part of a cell do viruses take on living characteristics of their own, borrowing the host's biochemistry to reproduce.

As such, it's more accurate to think of viruses as part of the continuum between chemistry and biology, one that isn't clearly divided



什么是病毒

https://cutt.ly/ltTIqNe 病毒是一种包含在有机颗粒中的遗传物质,该颗粒会侵入活细胞并利用其宿主的代谢过程产生新一代病毒颗粒。
他们执行此操作的方式各不相同。有些人将他们的遗传物质插入宿主的DNA中,可以放置在那里,直到以后翻译。随着宿主细胞自我复制,它可以制造新病毒。
病毒还可以随着其数量的膨胀而破裂其宿主细胞,这就是所谓的繁殖裂解周期。

病毒有多大?
病毒一词来自拉丁语,描述有毒液体。这是因为分离和成像微生物的早期形式无法捕获如此微小的颗粒。
病毒的大小从极小的微粒(例如17纳米宽的猪圆环病毒)到挑战“病毒”定义的怪物,例如2.3微米的Tupanvirus。into living and non-living.

同样,它们具有一系列复杂性,包含不同的蛋白质,或者被一系列的壳和包膜包围,以帮助它们感染和繁殖每个生命王国中的几乎每个物种。

病毒可以通过多种方式进行编码。轮状病毒例如基于RNA的双链。冠状病毒具有单链RNA,具有“正向意义”,因为它可以直接翻译成新蛋白质。流感具有负义RNA,这意味着它需要额外的转录步骤才能制造蛋白质。

天花和疱疹病毒就是DNA病毒的例子,它们迫使宿主在进入时将其基因组转录成RNA。

这些基因组的大小也不同。最大的一些可能超过一百万个碱基对。另一方面,一种感染细菌的RNA病毒,称为MS2,仅有3500个碱基对。

无法确定自然世界中存在多少种病毒,随着研究人员使用新工具在土壤,海洋甚至天空中寻找机密和未知的遗传特征,数字正在攀升。粗略估计表明,地球表面上可能有多达1亿种病毒。

病毒还活着吗?
随着生命和生态变化的定义,这是科学家继续讨论的问题。当前的想法表明,应将病毒视为复杂的生命系统的一部分,该系统在所有生物之间传播。
“病毒粒子”是在环境中移动的惰性粒子,我们通常不认为它们是活的。病毒一旦进入细胞,它们便会发挥自身的生存特征,借用宿主的生物化学进行繁殖。
因此,将病毒视为化学和生物学之间连续体的一部分是更准确的,这没有明确划分






How Long Does Coronavirus Last on Surfaces? #virusinfection, #Coronaviruswarning, #coronavirustips, #auckalndrepair, #davidlimnz


How Long Does Coronavirus Last on Surfaces?

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The coronavirus responsible for the disease COVID-19 can remain intact on surfaces for anywhere up to 72 hours, according to a study conducted by US researchers.


The precise figure depends heavily on the type of surface infected droplets land on, and might also rely on the density of virus particles in the spray, and other environmental conditions - such as temperature and sunlight.

But with so many particles found to still be infectious after being in the air for a number of hours, the evidence shows why we need to be so concerned with simple hygiene.

Scientists from the National Institute of Allergy and Infectious Diseases, the Centers for Disease Control, Princeton University, and University of California, Los Angeles, experimented with the SARS-CoV-2 virus under laboratory conditions to determine how fast virus particles broke down outside of a host body.

Click this link for the full article....

A woman sits cross-legged on a couch, under a blanket, blowing her nose



冠状病毒在表面持续多长时间?

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根据美国研究人员进行的一项研究,导致COVID-19病的冠状病毒可以在表面上保持完整状态长达72小时。
精确的数字在很大程度上取决于落在地面上的被感染小滴的类型,还可能取决于喷雾中病毒颗粒的密度以及其他环境条件(例如温度和阳光)。
但是,在空气中放置多个小时后发现仍有许多微粒仍具有传染性,因此有证据表明,为什么我们需要如此关注简单的卫生。
美国国家过敏和传染病研究所,普林斯顿大学疾病控制中心和加利福尼亚大学洛杉矶分校的科学家在实验室条件下对SARS-CoV-2病毒进行了实验,以确定病毒颗粒在体外快速分解的速度。主机。
先前研究有关冠状病毒动物和人类株的文献的研究提供了对该病毒在环境中移动时保持其完整性的能力的深入了解。但是直到现在,有关新SARS-CoV-2的实验证据仍很有限。
还对2003年SARS流行病背后的病毒SARS-CoV-1进行了比较测试,将两种病原体的菌株以微米级的液滴形式喷洒在包括纸板,铜和塑料在内的各种表面上。
只是在大气中徘徊,紫外线和热等因素的作用导致构成颗粒的RNA,脂肪膜和蛋白质的混合物在数小时内稳定分解。
两种病毒株掉落到塑料上后似乎可以保持更长的时间。例如,在不到七个小时的时间内,只有一半的SARS-CoV-2颗粒破裂,直到三天后仍检测到了存活的冠状病毒颗粒。
不锈钢几乎一样糟糕,SARS-CoV-2的半衰期为5.6小时。
另一方面,铜不能为任何一种菌株提供类似的保护,SARS-CoV-2能够在短短四个小时内消失,SARS-CoV-1能够在八小时内消失的能够引起疾病的存活颗粒的数量就消失了。
同样,在硬纸板上,在24小时后或在8小时后都找不到SARS-CoV-1可行的颗粒。
仍然需要记住许多变量。各个结果的差异表明,细微差异会影响时序。
实验室也保持在摄氏21-23度的恒定温度和65%的湿度下。这种最新病毒在光照,湿度和温度的其他条件下的行为方式尚待观察。
这对COVID-19大流行意味着什么?
2003年,SARS-CoV-1在26个国家/地区蔓延到中国,造成8,000多种已知感染。 2020年SARS-CoV-2大流行已经远远超过了以前的冠状病毒感染的速度和范围,导致研究人员研究造成这种差异的原因。
由于排除了他们在环境中保持生存能力的差异,因此还需要考虑其他可能性,包括被感染个体无法以相同方式出现症状的可能性。
在更实际的方面,该研究重申了对表面(尤其是塑料和不锈钢制成的表面)进行消毒的必要性。此外,触摸这些表面中的任何一个之后,重要的是要用肥皂和水洗手。

尽管每种菌株的数字并不相同,但它们足够相似,令人质疑为什么两种流行病以如此显着不同的方式传播。


这项研究发表在《新英格兰医学杂志》上。