{"id":3625,"date":"2021-11-17T12:52:23","date_gmt":"2021-11-17T17:52:23","guid":{"rendered":"https:\/\/abudinen.com\/blog\/?p=3625"},"modified":"2021-11-17T12:52:24","modified_gmt":"2021-11-17T17:52:24","slug":"chemicals","status":"publish","type":"post","link":"https:\/\/abudinen.com\/blog\/2021\/11\/17\/chemicals\/","title":{"rendered":"Chemicals"},"content":{"rendered":"\nComparing SARS-CoV-2 natural immunity to vaccine-induced immunity: reinfections versus breakthrough infections\n\n\n\nSivan&nbsp;Gazit,&nbsp;Roei&nbsp;Shlezinger,&nbsp;Galit&nbsp;Perez,&nbsp;Roni&nbsp;Lotan,&nbsp;Asaf&nbsp;Peretz,&nbsp;Amir&nbsp;Ben-Tov,&nbsp;Dani&nbsp;Cohen,&nbsp;Khitam&nbsp;Muhsen,&nbsp;Gabriel&nbsp;Chodick,&nbsp;Tal&nbsp;Patalondoi:&nbsp; article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should&nbsp;not&nbsp;be used to guide clinical practice. \n\n\n\nAbstract\n\n\n\nBackground&nbsp;Reports of waning vaccine-induced immunity against COVID-19 have begun to surface. With that, the comparable long-term protection conferred by previous infection with SARS-CoV-2 remains unclear.\n\n\n\nMethods&nbsp;We conducted a retrospective observational study comparing three groups: (1)SARS-CoV-2-na\u00efve individuals who received a two-dose regimen of the BioNTech\/Pfizer mRNA BNT162b2 vaccine, (2)previously infected individuals who have not been vaccinated, and (3)previously infected&nbsp;and&nbsp;single dose vaccinated individuals. Three multivariate logistic regression models were applied. In all models we evaluated four outcomes: SARS-CoV-2 infection, symptomatic disease, COVID-19-related hospitalization and death. The follow-up period of June 1 to August 14, 2021, when the Delta variant was dominant in Israel.\n\n\n\nResults<span class=\"maquina-leer-mas\">[...x]<\/span><div id=\"premium-content-gate\" style=\"display:none;\" class=\"contenido-premium\">strong>&nbsp;SARS-CoV-2-na\u00efve vaccinees had a 13.06-fold (95% CI, 8.08 to 21.11) increased risk for breakthrough infection with the Delta variant compared to those previously infected, when the first event (infection or vaccination) occurred during January and February of 2021. The increased risk was significant (<em>P<\/em>&lt;0.001) for symptomatic disease as well. When allowing the infection to occur at any time before vaccination (from March 2020 to February 2021), evidence of waning natural immunity was demonstrated, though SARS-CoV-2 na\u00efve vaccinees had a 5.96-fold (95% CI, 4.85 to 7.33) increased risk for breakthrough infection and a 7.13-fold (95% CI, 5.51 to 9.21) increased risk for symptomatic disease. SARS-CoV-2-na\u00efve vaccinees were also at a greater risk for COVID-19-related-hospitalizations compared to those that were previously infected.<\/p>\n\n\n\n<p id=\"p-7\"><strong>Conclusions<\/strong>&nbsp;This study demonstrated that natural immunity confers longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity. Individuals who were both previously infected with SARS-CoV-2 and given a single dose of the vaccine gained additional protection against the Delta variant.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Article<\/li><li>Open Access<\/li><li>Published:&nbsp;<time datetime=\"2021-06-14\">14 June 2021<\/time><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Naturally enhanced neutralizing breadth against SARS-CoV-2 one year after infection<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li>Zijun Wang,&nbsp;<\/li><li>Frauke Muecksch,&nbsp;<\/li><li>[\u2026]<\/li><li>Michel C. Nussenzweig&nbsp;<\/li><\/ul>\n\n\n\n<p><em>Nature<\/em>&nbsp;<strong>volume&nbsp;595<\/strong>,&nbsp;pages426\u2013431 (2021)Cite this article<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>158k&nbsp;Accesses<\/li><li>56&nbsp;Citations<\/li><li>3033&nbsp;Altmetric<\/li><li>Metricsdetails<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"Abs1\">Abstract<\/h3>\n\n\n\n<p>More than one year after its inception, the coronavirus disease&nbsp;2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus&nbsp;2 (SARS-CoV-2) remains difficult to control despite the availability of several working vaccines. Progress in controlling the pandemic is slowed by the emergence of variants that appear to be more transmissible and more resistant to antibodies<sup>1,2<\/sup>. Here we report on a cohort of 63 individuals who have recovered from COVID-19 assessed at 1.3, 6.2 and 12 months after SARS-CoV-2 infection, 41% of whom also received mRNA vaccines<sup>3,4<\/sup>. In the absence of vaccination, antibody reactivity to the receptor binding domain (RBD) of SARS-CoV-2, neutralizing activity and the number of RBD-specific memory B cells remain relatively stable between 6 and 12 months after infection. Vaccination increases all components of the humoral response and, as expected, results in serum neutralizing activities against variants of concern similar to or greater than the neutralizing activity against the original Wuhan Hu-1 strain achieved by vaccination of naive individuals<sup>2,5,6,7,8<\/sup>. The mechanism underlying these broad-based responses involves ongoing antibody somatic mutation, memory B cell clonal turnover and development of monoclonal antibodies that are exceptionally resistant to SARS-CoV-2 RBD mutations, including those found in the variants of concern<sup>4,9<\/sup>. In addition, B cell clones expressing broad and potent antibodies are selectively retained in the repertoire over time and expand markedly after vaccination. The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants. <\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Junked food! Toxic compounds used to make industrial tubing and rubber gloves are found in 80% of McDonald&#8217;s, Burger King and Pizza Hut food: Dangerous chemicals are linked to asthma, infertility and smaller testicles, study finds<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Researchers tested 64 top menu items from&nbsp;McDonald&#8217;s, Burger King, Pizza Hut, Domino&#8217;s, Taco Bell, and Chipotle<\/strong><\/li><li><strong>Almost tested positive for phthalates, compounds that make plastic more pliable<\/strong><\/li><li><strong>Eighty percent contained a phthalate linked to a heightened risk for asthma, and 70 percent to one tied to reduced fertility<\/strong><\/li><li><strong>Items made with meat had higher levels of phthalates, while French&nbsp;fries and cheese pizza had the lowest&nbsp;<\/strong><\/li><\/ul>\n\n\n\n<p>By&nbsp;DAN AVERY FOR DAILYMAIL.COM<\/p>\n\n\n\n<p><strong>PUBLISHED:<\/strong>&nbsp;18:14 GMT, 27 October 2021&nbsp;|&nbsp;<strong>UPDATED:<\/strong>&nbsp;18:17 GMT, 27 October 2021 People are exposed to phthalates by ingesting foods and beverages that have contacted products containing phthalates or by breathing phthalate particles in the air directly, according to the&nbsp;Centers for Disease Control and Prevention.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"content\">Phthalates Factsheet<\/h2>\n\n\n\n<p>Phthalates are a group of chemicals used to make plastics more durable. They are often called plasticizers. Some phthalates are used to help dissolve other materials. Phthalates are in hundreds of products, such as vinyl flooring, lubricating oils, and personal-care products (soaps, shampoos, hair sprays).<\/p>\n\n\n\n<p>Some phthalates are in polyvinyl chloride plastics, which are used to make products such as plastic packaging, garden hoses, and medical tubing.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How People Are Exposed to Phthalates<\/h3>\n\n\n\n<p>People are exposed to phthalates by eating and drinking foods that have contacted products containing phthalates. Some exposure can occur from breathing phthalate particles in the air. Children crawl around and touch many things, then put their hands in their mouths. Because of that hand-to-mouth behavior, phthalate particles in dust might be a greater risk for children than for adults. Inside a person\u2019s body, phthalates are converted into breakdown products (metabolites) that quickly leave the body in urine.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How Phthalates Affect People\u2019s Health<\/h3>\n\n\n\n<p>Some types of phthalates have affected the reproductive system in animals. Human health effects from exposure to low levels of phthalates are not as clear. More research is needed to assess the human health effects of exposure to phthalates.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Levels of Phthalate Metabolites in the U.S. Population<\/h3>\n\n\n\n<p>By measuring phthalate metabolites in urine, scientists can estimate the amount of phthalates that have entered people\u2019s bodies. CDC scientists measured 13 phthalate metabolites in the urine of 2,636 or more people aged 6 years and older who took part in the National Health and Nutrition Examination Survey (NHANES) during 2003\u20132004. CDC published these findings in the&nbsp;<em><u>Fourth National Report on Human Exposure to Environmental Chemicals.<\/u><\/em><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>CDC researchers found measurable levels of many phthalate metabolites in the general population. This finding indicates that phthalate exposure is widespread in the U.S. population.<\/li><li>Adult women have higher levels of metabolites measured in urine than do men for those phthalates that are used in soaps, body washes, shampoos, cosmetics, and similar personal care products.<\/li><li>Non-Hispanic Blacks have higher levels of exposure for several phthalates and phthalate alternative metabolites than do Non-Hispanic Whites.<\/li><\/ul>\n\n\n\n<p>Finding a detectable amount of phthalate metabolites in urine does not mean the levels will cause harmful health effects. Biomonitoring studies measure levels of chemicals, such as phthalate metabolites, that people have in their bodies. Levels that are not likely to cause harm are called reference values. Physicians and public health officials use reference values to decide if people have been exposed to higher levels of these chemicals than are found in the general population. Biomonitoring data can help scientists plan and conduct research on exposure and health effects.<\/p>\n\n\n\n<p>&#8212;<br>Items made with meat had higher levels of phthalates, while French fries and cheese pizza had the lowest, according to their findings, published in the&nbsp;Journal of Exposure Science and Environmental Epidemiology.&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Article<\/li><li>Open Access<\/li><li>Published:&nbsp;<time datetime=\"2021-10-27\">27 October 2021<\/time><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Phthalate and novel plasticizer concentrations in food items from U.S. fast food chains: a preliminary analysis<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li>Lariah Edwards,&nbsp;<\/li><li>Nathan L. McCray,&nbsp;<\/li><li>Brianna N. VanNoy,&nbsp;<\/li><li>Alice Yau,&nbsp;<\/li><li>Ruth J. Geller,&nbsp;<\/li><li>Gary Adamkiewicz&nbsp;&amp;&nbsp;<\/li><li>Ami R. Zota&nbsp;<\/li><\/ul>\n\n\n\n<p><em>Journal of Exposure Science &amp; Environmental Epidemiology<\/em>&nbsp;(2021)Cite this article <\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>36k&nbsp;Accesses<\/li><li>807&nbsp;Altmetric<\/li><li>Metrics<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"Abs1\">Abstract<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">Background<\/h4>\n\n\n\n<p>Fast food consumption is associated with biomarkers of ortho-phthalates exposures. However, the chemical content of fast food is unknown; certain ortho-phthalates (i.e., di-<em>n<\/em>-butyl phthalate (DnBP) and di(2-ethylhexyl) phthalate (DEHP)) have been phased out and replaced with other plasticizers (e.g., dioctyl terephthalate (DEHT)).<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Objective<\/h4>\n\n\n\n<p>We conducted a preliminary study to examine ortho-phthalate and replacement plasticizer concentrations in foods and food handling gloves from U.S. fast food restaurants.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Methods<\/h4>\n\n\n\n<p>We obtained hamburgers, fries, chicken nuggets, chicken burritos, cheese pizza (<em>n<\/em>\u2009=\u200964 food samples) and gloves (<em>n<\/em>\u2009=\u20093) from restaurants and analyzed them for 11 chemicals using gas chromatography mass spectrometry.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Results<\/h4>\n\n\n\n<p>We found DEHT at the highest concentrations in both foods (<em>n<\/em>\u2009=\u200919; median\u2009=\u20092510\u2009\u00b5g\/kg; max\u2009=\u200912,400\u2009\u00b5g\/kg) and gloves (<em>n<\/em>\u2009=\u20093; range: 28\u201337% by weight). We detected DnBP and DEHP in 81% and 70% of food samples, respectively. Median DEHT concentrations were significantly higher in burritos than hamburgers (6000\u2009\u00b5g\/kg vs. 2200\u2009\u00b5g\/kg;&nbsp;<em>p<\/em>\u2009&lt;\u20090.0001); DEHT was not detected in fries. Cheese pizza had the lowest levels of most chemicals.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Significance<\/h4>\n\n\n\n<p>To our knowledge, these are the first measurements of DEHT in food. Our preliminary findings suggest that ortho-phthalates remain ubiquitous and replacement plasticizers may be abundant in fast food meals.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Impact statement<\/h4>\n\n\n\n<p>A selection of popular fast food items sampled in this study contain detectable levels of replacement plasticizers and concerning ortho-phthalates. In addition, food handling gloves contain replacement plasticizers, which may be a source of food contamination. These results, if confirmed, may inform individual and regulatory exposure reduction strategies.<\/p>\n\n\n\n<p>&#8212;<br>&#8216;Disadvantaged neighborhoods often have plenty of fast-food outlets but limited access to healthier foods like fruits and vegetables,&#8217; Zota told&nbsp;The Washington Post. &#8216;Additional research needs to be done to find out whether people living in such food deserts are at higher risk of exposure to these harmful chemicals.&#8217;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"main-content\">Some fast-food items contain plastics linked to serious health problems, new report shows<\/h2>\n\n\n\n<p>Chemicals that research has shown to be linked to reproductive harm and learning problems in children were found in popular menu items Listen to article5 min <\/p>\n\n\n\n<p>&#8212;<br>A&nbsp;2019 CDC report&nbsp;found non-Latino blacks have higher levels of exposure to several phthalates and phthalate alternatives than whites. <\/p>\n\n\n\n<p>The FDA doesn&#8217;t set limits for phthalates in food, according to the Post, but the levels detected in the 64 fast-food items purchased from franchises around San Antonio, Texas, were all below&nbsp;the EPA&#8217;s current acceptable thresholds. <\/p>\n\n\n\n<p>Last week, the EPA said it was moving to regulate certain forever chemicals \u2014 known as Per- and polyfluoroalkyl substances, or PFAS \u2014 in U.S. drinking water after they have&nbsp;repeatedly appeared in water supplies&nbsp;across the country.<\/p>\n\n\n\n<p>The agency said it would also designate some as hazardous chemicals.<\/p>\n\n\n\n<p>PFAs are used to make cookware, rainwear, carpet and other items water- and stain-resistant, but&nbsp;have also been tied to health issues, including higher cholesterol, an increased risk of kidney and testicular cancer, and damage to the immune system, as well as&nbsp; birth defects, smaller birth weights, and decreased vaccine response in children.<\/p>\n\n\n\n<p><strong>What are the health effects of PFAS? <\/strong>A large number of studies have examined possible relationships between levels of per- and polyfluoroalkyl substances (PFAS) in blood and harmful health effects in people. However, not all of these studies involved the same groups of people, the same type of exposure, or the same PFAS. These different studies therefore reported a variety of health outcomes. <\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Toxic &#8216;forever chemicals&#8217; being leaked from nearly 42,000 sources like treatment plants and landfills could be polluting drinking water across the US, survey finds<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>The Environmental Working Group analyzed the EPA&#8217;s database of PFAS,&nbsp;manmade chemicals often added to common household products<\/strong><\/li><li><strong>PFAS never break down and, in some cases, are linked to health problems<\/strong><\/li><li><strong>Water sources most at risk of contamination were near landfills, wastewater treatment plants and petroleum refineries<\/strong><\/li><li><strong>The group argues no level of PFAS above 1 part per trillion is safe<\/strong><\/li><li><strong>It&#8217;s urging the EPA to take a stronger stance to limit these chemicals<\/strong><\/li><\/ul>\n\n\n\n<p>By&nbsp;DAN AVERY FOR DAILYMAIL.COM<\/p>\n\n\n\n<p><strong>PUBLISHED:<\/strong>\u00a022:01 GMT, 13 October 2021\u00a0|\u00a0<strong>UPDATED:<\/strong>\u00a016:45 GMT, 27 October 2021 <\/p>\n\n\n\n<p><strong>La Venecia de Pac\u00edfico<\/strong> En la isla de Pophei, en Micronesia, se encuentra uno de los lugares m\u00e1s misteriosos del planeta: las ruinas de Nan Madol (en la foto), que ocultan bajo las aguas una ciudad sumergida de, seg\u00fan algunos, 12.000 a\u00f1os de antig\u00fcedad. Bautizada como la Venecia del Pac\u00edfico, el complejo arqueol\u00f3gico se extiende m\u00e1s de 18 kil\u00f3metros cuadrados, con arquitectura megal\u00edtica y casi cien islotes artificiales (de piedra y coral) rodeados por canales. <\/p>\n\n\n\n<p><strong>Racchi<\/strong>&nbsp;(quechua:&nbsp;<em>Raqchi<\/em>) es un sitio arqueol\u00f3gico&nbsp;incaico&nbsp;ubicado en el distrito de&nbsp;San Pedro&nbsp;de Cachas en la&nbsp;provincia de Canchis&nbsp;(Cuzco,&nbsp;Per\u00fa). El sitio arqueol\u00f3gico tambi\u00e9n es conocido como el templo de&nbsp;Viracocha&nbsp;debido a una de sus construcciones emblem\u00e1ticas. Se encuentra cercano al pueblo de Raqchi y al&nbsp;r\u00edo Vilcanota.<\/p>\n\n\n\n<p><strong>Conrad Haas<\/strong>&nbsp;(1509\u20131576) was an Austrian or a&nbsp;Transylvanian Saxon&nbsp;military engineer&nbsp;from the&nbsp;Kingdom of Hungary,&nbsp;Transylvania. He was a pioneer of&nbsp;rocket propulsion. His designs include a&nbsp;three-stage rocket&nbsp;and a manned rocket.<\/p>\n\n\n\n<p>An illustration and description in the 14th century&nbsp;Chinese<em>Huolongjing<\/em>&nbsp;by&nbsp;Jiao Yu&nbsp;and&nbsp;Liu Bowen&nbsp;shows the oldest known multistage rocket; this was the &#8220;fire-dragon issuing from the water&#8221; (\u706b\u9f99\u51fa\u6c34, hu\u01d2 l\u00f3ng ch\u016b shu\u01d0), used mostly by the Chinese navy.<sup>[7][8]<\/sup>&nbsp;It was a two-stage rocket that had&nbsp;booster rockets&nbsp;that would eventually burn out, yet before they did they automatically ignited a number of smaller rocket arrows that were shot out of the front end of the missile, which was shaped like a dragon&#8217;s head with an open mouth.<sup>[8]<\/sup>&nbsp;This multi-stage rocket may be considered the ancestor to the modern&nbsp;YingJi-62ASCM.<sup>[8][9]<\/sup>&nbsp;The British scientist and historian&nbsp;Joseph Needham&nbsp;points out that the written material and depicted illustration of this rocket come from the oldest stratum of the&nbsp;<em>Huolongjing<\/em>, which can be dated roughly 1300\u20131350 AD (from the book&#8217;s part 1, chapter 3, page 23).<sup>[8]<\/sup><\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>&nbsp;&#8220;\u706b\u9f99\u51fa\u6c34\uff08\u660e\uff09\u7b80\u4ecb&#8221;. \u661f\u8fb0\u5728\u7ebf. 2003-12-26. Archived from&nbsp;the original&nbsp;on March 3, 2009. Retrieved&nbsp;July 17,&nbsp;2008.<\/li><li>^&nbsp;<sup><em><strong>a<\/strong><\/em><\/sup>&nbsp;<sup><em><strong>b<\/strong><\/em><\/sup>&nbsp;<sup><em><strong>c<\/strong><\/em><\/sup>&nbsp;<sup><em><strong>d<\/strong><\/em><\/sup>&nbsp;Needham, Volume 5, Part 7, 510.<\/li><li><strong>^<\/strong>&nbsp;&#8220;\u4e2d\u56fdYJ-62\u65b0\u578b\u8fdc\u7a0b\u53cd\u8230\u5bfc\u5f39&#8221;. \u5927\u65d7\u7f51. 2007-09-30. Retrieved&nbsp;July 17,&nbsp;2008.<sup>[<em>permanent dead link<\/em>]<\/sup><\/li><\/ol>\n\n\n\n<p><strong>Jiao Yu<\/strong>&nbsp;(Chinese:&nbsp;\u7126\u7389;&nbsp;pinyin:&nbsp;<em><strong>Ji\u0101o Y\u00f9<\/strong><\/em>;&nbsp;Wade\u2013Giles:&nbsp;<em><strong>Chiao Y\u00fc<\/strong><\/em>) was a Chinese military general, philosopher, and writer of the Ming dynasty under&nbsp;Zhu Yuanzhang, who founded the dynasty and became known as the Hongwu Emperor. He was entrusted by Zhu as a leading&nbsp;artillery&nbsp;officer for the rebel army that overthrew the&nbsp;MongolYuan dynasty, and established the Ming Dynasty.<sup>[1]<\/sup>&nbsp;As a senior adviser and general, he was later appointed to the venerable and noble status of the&nbsp;Count&nbsp;of Dongning.<sup>[2]<\/sup>&nbsp;He edited and wrote a famous military treatise that outlined the use of Chinese military technology during the mid 14th century based on his military campaign of 1355 AD.<sup>[1]<\/sup>&nbsp;However, descriptions of some&nbsp;gunpowder&nbsp;weapons in his treatise derive from&nbsp;Song Dynasty&nbsp;(960\u20131279 AD) materials on battles against the&nbsp;Khitans,&nbsp;Jurchens&nbsp;and&nbsp;Mongols. His&nbsp;<em>Huolongjing<\/em>, translated as the&nbsp;<em>Fire Drake Manual<\/em>, contains descriptions of&nbsp;fire arrows,&nbsp;fire lances,&nbsp;grenades,&nbsp;firearms,&nbsp;bombards,&nbsp;cannons,&nbsp;exploding cannonballs,&nbsp;land mines,&nbsp;naval mines,&nbsp;rockets,&nbsp;rocket launchers, two-stage rockets, and various gunpowder solutions including&nbsp;poisonous&nbsp;concoctions.<\/p>\n\n\n\n<p><sup>[1]<\/sup>&nbsp;Needham, Volume 5, Part 7, 26. <sup>[2]<\/sup>&nbsp;Needham, Volume 5, Part 7, 31.<\/p>\n\n\n\n<p>Needham, Joseph (1986).&nbsp;<em>Science and Civilization in China: Volume 5, Chemistry and Chemical Technology, Part 7, Military Technology; the Gunpowder Epic<\/em>. Taipei: Caves Books Ltd.<\/p>\n\n\n\n<p>Las mejoras en la tecnolog\u00eda militar ayudaron a la dinast\u00eda Song a defenderse de sus vecinos hostiles del norte. El&nbsp;lanzallamas&nbsp;tuvo sus or\u00edgenes hacia el&nbsp;siglo VII&nbsp;en la&nbsp;Greciabizantina, y su funci\u00f3n era arrojar&nbsp;fuego griego&nbsp;(un fluido a base de&nbsp;petr\u00f3leo&nbsp;con&nbsp;f\u00f3rmula qu\u00edmica&nbsp;compleja y altamente&nbsp;inflamable) mediante una&nbsp;manguera de sif\u00f3n.<sup>[48]<\/sup><\/p>\n\n\n\n<p>Needham, vol. 5, 7\u00aa parte, 77.<\/p>\n\n\n\n<p><strong>Beam-powered propulsion<\/strong>, also known as directed energy propulsion, is a class of&nbsp;aircraft&nbsp;or&nbsp;spacecraft propulsion&nbsp;that uses energy beamed to the spacecraft from a remote power plant to provide energy. The beam is typically either a&nbsp;microwave&nbsp;or a&nbsp;laser&nbsp;beam and it is either pulsed or continuous.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Comparing SARS-CoV-2 natural immunity to vaccine-induced immunity: reinfections versus breakthrough infections Sivan&nbsp;Gazit,&nbsp;Roei&nbsp;Shlezinger,&nbsp;Galit&nbsp;Perez,&nbsp;Roni&nbsp;Lotan,&nbsp;Asaf&nbsp;Peretz,&nbsp;Amir&nbsp;Ben-Tov,&nbsp;Dani&nbsp;Cohen,&nbsp;Khitam&nbsp;Muhsen,&nbsp;Gabriel&nbsp;Chodick,&nbsp;Tal&nbsp;Patalondoi:&nbsp; article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should&nbsp;not&nbsp;be used to guide clinical practice. Abstract Background&nbsp;Reports of waning vaccine-induced immunity against COVID-19 have begun to &#8230; <a title=\"Chemicals\" class=\"read-more\" href=\"https:\/\/abudinen.com\/blog\/2021\/11\/17\/chemicals\/\" aria-label=\"Read more about Chemicals\">Leer m\u00e1s<\/a><\/p>\n\n        <p class=\"social-share\">\n            <strong><span>Sharing is caring<\/span><\/strong> <!--<i class=\"fa fa-share-alt\"><\/i>&nbsp;&nbsp;-->\n            <a href=\"https:\/\/www.facebook.com\/sharer.php?u=https%3A%2F%2Fabudinen.com%2Fblog%2F2021%2F11%2F17%2Fchemicals%2F\" target=\"_blank\" class=\"facebook\"><i class=\"fab fa-facebook\"><\/i> <span>Share<\/span><\/a>\n            <a href=\"https:\/\/plus.google.com\/share?url=https%3A%2F%2Fabudinen.com%2Fblog%2F2021%2F11%2F17%2Fchemicals%2F\" target=\"_blank\" class=\"gplus\"><i class=\"fab fa-google-plus\"><\/i> <span>+1<\/span><\/a>\n            <a href=\"https:\/\/twitter.com\/intent\/tweet?text=Chemicals&amp;url=https%3A%2F%2Fabudinen.com%2Fblog%2F2021%2F11%2F17%2Fchemicals%2F&amp;via=YOUR_TWITTER_HANDLE_HERE\" target=\"_blank\" class=\"twitter\"><i class=\"fab fa-twitter\"><\/i> <span>Tweet<\/span><\/a>\n            <a href=\"http:\/\/www.linkedin.com\/shareArticle?mini=true&amp;url=Chemicals\" target=\"_blank\" class=\"linkedin\"><i class=\"fab fa-linkedin\"><\/i> <span>Share<\/span><\/a>\n            <a href=\"https:\/\/wa.me\/?text=Chemicals https%3A%2F%2Fabudinen.com%2Fblog%2F2021%2F11%2F17%2Fchemicals%2F\" target=\"_blank\" class=\"whatsapp\"><i class=\"fab fa-whatsapp\"><\/i> <span>Share<\/span><\/a>\n            <w>2887 words 113 views<\/w>\n        <\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3625","post","type-post","status-publish","format-standard","hentry","category-sin-categoria"],"_links":{"self":[{"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/posts\/3625","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/comments?post=3625"}],"version-history":[{"count":30,"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/posts\/3625\/revisions"}],"predecessor-version":[{"id":3817,"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/posts\/3625\/revisions\/3817"}],"wp:attachment":[{"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/media?parent=3625"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/categories?post=3625"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/abudinen.com\/blog\/wp-json\/wp\/v2\/tags?post=3625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}