#干细胞资讯# 柳叶刀：新冠大流行的真正影响——1600万人死亡，全球预期寿命降低1.6岁
2024年3月11日，国际顶尖医学期刊《柳叶刀》发表了一项题为：Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021 的研究论文。
这项大型研究表明，新冠疫情在头两年里（2020-2021年）导致全球人口的平均预期寿命下降了1.6年，这一比之前预计的下降幅度更大，标志着全球预期寿命数十年来的增长出现了急剧逆转。
在2020-2021年，全球估计有1.31亿人因各种原因死亡，其中约1590万人死于COVID-19大流行（以超额死亡率衡量，包括直接由新冠病毒感染引起的死亡和间接由与大流行相关的其他社会、经济或行为变化引起的死亡）。有80个国家和地区在至少一年的疫情期间，超额死亡率超过了150人/10万人。
2024年3月11日，国际顶尖医学期刊《柳叶刀》发表了一项题为：Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021 的研究论文。
这项大型研究表明，新冠疫情在头两年里（2020-2021年）导致全球人口的平均预期寿命下降了1.6年，这一比之前预计的下降幅度更大，标志着全球预期寿命数十年来的增长出现了急剧逆转。
在2020-2021年，全球估计有1.31亿人因各种原因死亡，其中约1590万人死于COVID-19大流行（以超额死亡率衡量，包括直接由新冠病毒感染引起的死亡和间接由与大流行相关的其他社会、经济或行为变化引起的死亡）。有80个国家和地区在至少一年的疫情期间，超额死亡率超过了150人/10万人。
发点文献
Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
本来困得要命，看到这篇大文章瞬间醒了
做GBD数据的打工人该回去赶工了。。。
Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
本来困得要命，看到这篇大文章瞬间醒了
做GBD数据的打工人该回去赶工了。。。
Why do some people seem to be naturally colder than others? The answer may surprise you, and it has a lot more to do with metabolism and body type than you might think.
Like all mammals, humans use chemical reactions in our bodies to keep our internal temperature toasty, and consistently so. To create this life-giving heat, we have metabolism: A series of chemical reactions that takes place within the cells of living organisms. Think of metabolism like a car's engine: It takes in fuel (food, in our case), burns it, and uses the resultant energy to produce motion and heat.
While humans don't literally "burn" our food to harness its energy, one of these metabolic processes involves a similar, less explosive reaction called respiration. And like an open flame, this, too, requires oxygen.
It's estimated that nearly 50% of the calories we consume just go toward maintaining our body temperature, according to a 2019 paper published in Current Biology. To ensure that this extra heat isn't wasted, we also have numerous adaptations to make sure we don't drop in temperature too quickly.
Our bodies also automatically constrict blood flow to extremities like the hands and feet when the cold hits, so we lose less heat to our surroundings. Since heat loss occurs at the skin-air interface, the more surface area you have exposed, the more you're likely to lose your hard-earned body warmth to a chilly winter's day.
By the same token, those with less circulation to their limbs often have a harder time getting warm, since less heated blood from the rest of the body passes by.
This ratio of heat-generating volume to heat-losing surface area affects our propensity to get cold, as well. As such, a smaller body tends to lose more heat, since it has less volume to compensate for a comparatively higher area.
And the smaller you get, the harder it is to prevent this heat loss. The discrepancy can be affected by sex, as well. Women tend to be colder than men, on average, due to having generally smaller bodies.
In a 2021 study published in Energy and Buildings, researchers found that most of the female participants surveyed were less comfortable in slightly chilly temperatures than the male participants, due to different metabolic rates and sweat responses. On the flipside, the men tended to sweat more in the heat.
Like all mammals, humans use chemical reactions in our bodies to keep our internal temperature toasty, and consistently so. To create this life-giving heat, we have metabolism: A series of chemical reactions that takes place within the cells of living organisms. Think of metabolism like a car's engine: It takes in fuel (food, in our case), burns it, and uses the resultant energy to produce motion and heat.
While humans don't literally "burn" our food to harness its energy, one of these metabolic processes involves a similar, less explosive reaction called respiration. And like an open flame, this, too, requires oxygen.
It's estimated that nearly 50% of the calories we consume just go toward maintaining our body temperature, according to a 2019 paper published in Current Biology. To ensure that this extra heat isn't wasted, we also have numerous adaptations to make sure we don't drop in temperature too quickly.
Our bodies also automatically constrict blood flow to extremities like the hands and feet when the cold hits, so we lose less heat to our surroundings. Since heat loss occurs at the skin-air interface, the more surface area you have exposed, the more you're likely to lose your hard-earned body warmth to a chilly winter's day.
By the same token, those with less circulation to their limbs often have a harder time getting warm, since less heated blood from the rest of the body passes by.
This ratio of heat-generating volume to heat-losing surface area affects our propensity to get cold, as well. As such, a smaller body tends to lose more heat, since it has less volume to compensate for a comparatively higher area.
And the smaller you get, the harder it is to prevent this heat loss. The discrepancy can be affected by sex, as well. Women tend to be colder than men, on average, due to having generally smaller bodies.
In a 2021 study published in Energy and Buildings, researchers found that most of the female participants surveyed were less comfortable in slightly chilly temperatures than the male participants, due to different metabolic rates and sweat responses. On the flipside, the men tended to sweat more in the heat.
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