The World Health Organization declared Sri Lanka a malaria eliminated country in 2016[1-3].At present,the country is in the phase of preventing the re-establishment of malaria[4].However,travelers who contract the dis...The World Health Organization declared Sri Lanka a malaria eliminated country in 2016[1-3].At present,the country is in the phase of preventing the re-establishment of malaria[4].However,travelers who contract the disease overseas in malaria endemic countries continue to present a constant risk of re-establishing malaria in Sri Lanka,where malaria-transmitting mosquitos is prevalent.In this context,robust measures are being implemented in the country to prevent re-establishment of malaria and to stop travelers infected with malaria progressing into severe disease and death.展开更多
Nowadays, distributing network-connected photovoltaic (PV) systems are expanded by merging a PV system and a Direct Current (DC)/Alternating Current (AC) energy converter. DC/AC conversion of PV energy is in great dem...Nowadays, distributing network-connected photovoltaic (PV) systems are expanded by merging a PV system and a Direct Current (DC)/Alternating Current (AC) energy converter. DC/AC conversion of PV energy is in great demand for AC applications. The supply of electrical machines and transfer energy to the distribution network is a typical case. In this work, we study and design a DC/AC energy converter using harmonic selective eliminated (HSE) method. To this end, we have combined two power stages connected in derivation. Each power stage is constituted of transistors and transformers. The connection by switching of the two rectangular waves, delivered by each of the stages, makes it possible to create a quasi-sinusoidal output voltage of the inverter. Mathematical equations based on the current-voltage characteristics of the inverter have been developed. The simulation model was validated using experimental data from a 25.2 kWp grid-coupled (PV) system, connected to Gridfit type inverters. The data were exported and implemented in programming software. A good agreement was observed and this shows all the robustness and the technical performances of the energy converter device. It emerges from this analysis that the inverter output voltage and the phase angle thus simulated are very important to control in order to orientate the transfer of the power flow from the continuous cell to cell to the alternating part. Simulated and field-testing results also show that increases in the value of the modulation factor (m) for low power output are highly significant. This study is an important tool for DC/AC inverter designers during initial planning stages. A short presentation of the design model of the inverter has been proposed in this article.展开更多
The "expectations gap" signifies the differences between what the public expects from an audit and what the auditing profession prefers the audit objectives to be.Although the gap exists,it seems that the pr...The "expectations gap" signifies the differences between what the public expects from an audit and what the auditing profession prefers the audit objectives to be.Although the gap exists,it seems that the professions trust that it could be eliminated.In this paper,further evidence was provided to deny the above point by exploring the inevitability nature and the structure of the audit expectation gap.In addition,the author concludes that expectations gap cannot be eliminated;instead,the only thing can be done is to narrow down the gap.展开更多
Objective:To describe the situation of measles in Sri Lanka from May to November,2023 and to define the role of virology laboratory towards case confirmation and epidemiological and genetic characterization of the out...Objective:To describe the situation of measles in Sri Lanka from May to November,2023 and to define the role of virology laboratory towards case confirmation and epidemiological and genetic characterization of the outbreak.Methods:This retrospective study analyzed all samples tested for measles from 1st of May to 30th of November,2023 at National Measles Rubella Laboratory,Sri Lanka.According to the World Health Organization(WHO)algorithm,serum and oropharyngeal/nasopharyngeal swabs were tested with WHO recommended kits for anti-measles IgM and measles virus specific RNA,respectively.Selected RNA positive samples were sequenced at reference laboratory,India.Analysis of sequencing data and construction of phylogenetic tree were carried out at National Measles Rubella Laboratory.Data was analyzed using descriptive statistics.Results:Of the total 1132 serum samples and 497 oropharyngeal/nasopharyngeal swabs from 1326 patients,657(49.5%)patients were confirmed as measles by anti-measles IgM,measles virus specific RNA or both.Males(55.6%,n=365)and the age group from>20 to≤30 years(33.0%,n=217)predominated positive patients.All provinces reported measles positive cases.All samples sequenced(100%,n=42)were genotype D8 with 95.2%(n=40)bearing Victoria.Australia origin.Conclusions:We described resurgence of measles in an eliminated country,confirming the genotype to be D8,one of the two genotypes currently circulating globally.Further,the study strongly convinced the importance of a strengthened virological surveillance system in an eliminated country,despite its eliminated status.展开更多
[Objective] The aim was to explore the effect of eliminated the breeding pigs with unqualified CSFV antibody on sow's reproductive performance and pig's growth performance so as to provide a scientific basis f...[Objective] The aim was to explore the effect of eliminated the breeding pigs with unqualified CSFV antibody on sow's reproductive performance and pig's growth performance so as to provide a scientific basis for the eliminating of the breeding pigs with unqualified CSFV antibody in large-scale pig farms.[Method] Serum samples from three scale pig farms were collected and tested with HerdChek CSFV-ELISA kit,then provided a certain scientific basis for scale pig farm to eliminate the unqualified(antibody blocking rate<50%)breeders after booster immunization.[Result ] After eliminating the breeding pigs with unqualified CSFV antibody,the average litter number of piglet in three pig farms(A,B,C)were increased by 0.29(P<0.05),0.40(P<0.01),0.39(P<0.01)respectively;the average number of survival piglets were increased by 0.54(P<0.01),0.35(P<0.01),0.62(P<0.01)respectively;the average litter number of weaned piglets were increased by 0.65(P<0.01),0.71(P<0.01),0.81(P<0.01)respectively.The difference in weight gain of piglet at 30-60 d of age was extremely significant(P<0.01),but inconspicuousness for the swine pregnancy rate,the survival rate of weaned piglet and piglet at 30-60 d of age.[Conclusion] The eliminating the breeding pigs with unqualified CSFV antibody can significantly improve the performance of breeder and piglets.展开更多
The discoloration of Scot pine （Pinus sylvestris var. Mongolica） veneers caused by resin-eliminated treatment and the reversion of the color were studied. The result showed that the color of the veneers changed from...The discoloration of Scot pine （Pinus sylvestris var. Mongolica） veneers caused by resin-eliminated treatment and the reversion of the color were studied. The result showed that the color of the veneers changed from buff to yellowish brown after the treatment of resin elimination and the discoloration of heartwood was more severe than that of sapwood; the degree of discoloration was significantly positively correlated with the medicament strength, temperature and resin-eliminated duration. The variance analysis showed the effects of those three factors on the discoloration were significant. With hydrogen peroxide （H2O2） as color reversion medicament and inorganic compound as medium of the reaction, the reversion of the color of heartwood was more inaccessible than that of sapwood; the degree of the color’s reversion was positively correlated with the H2O2 strength, temperature and treating time; the H2O2 concentration has significant effects on the discoloration. In order to reduce discoloration of Scot pine veneers, medicament of resin-eliminated used have to be at some low concentration, and the optimal concentration of H2O2 is 0.35% during the process of color’s reversion.展开更多
The effect of terrain shadow, including the self and cast shadows, is one ofthe main obstacles for accurate retrieval of vegetation parameters byremote sensing in rugged terrains. A shadow- eliminated vegetation index...The effect of terrain shadow, including the self and cast shadows, is one ofthe main obstacles for accurate retrieval of vegetation parameters byremote sensing in rugged terrains. A shadow- eliminated vegetation index(SEVI) was developed, which was computed from only red and nearinfrared top-of-atmosphere reflectance without other heterogeneous dataand topographic correction. After introduction of the conceptual modeland feature analysis of conventional wavebands, the SEVI was constructedby ratio vegetation index (RVI), shadow vegetation index (SVI) andadjustment factor (f (Δ)). Then three methods were used to validate theSEVI accuracy in elimination of terrain shadow effects, including relativeerror analysis, correlation analysis between the cosine of solar incidenceangle (cosi) and vegetation indices, and comparison analysis between SEVIand conventional vegetation indices with topographic correction. Thevalidation results based on 532 samples showed that the SEVI relativeerrors for self and cast shadows were 4.32% and 1.51% respectively. Thecoefficient of determination between cosi and SEVI was only 0.032 and thecoefficient of variation (std/mean) for SEVI was 12.59%. The results indicatethat the proposed SEVI effectively eliminated the effect of terrain shadowsand achieved similar or better results than conventional vegetation indiceswith topographic correction.展开更多
Introduction:Cancer is a major health problem in China.Integrated interventions have been implemented in key areas of Anhui,Henan,Jiangsu,and Shandong provinces with historically higher than average cancer mortality.A...Introduction:Cancer is a major health problem in China.Integrated interventions have been implemented in key areas of Anhui,Henan,Jiangsu,and Shandong provinces with historically higher than average cancer mortality.Assessing the cancer mortality trend and its impact on life expectancy(LE)could help evaluate the effectiveness of interventions in these regions.Methods:Based on the National Cause-of-Death Surveillance,we analyzed the standardized mortality rate(SMR)of cancer,cause eliminated life expectancy(CELE),potential gains in life expectancy(PGLEs),and rate of life lost in key areas of 4 provinces from 2008 to 2018.Joinpoint program was used to compute the average annual percentage change(AAPC)of cancer mortality.Arriaga’s decomposition method was used to estimate the contribution of cancer to LE in each age group.Results:From 2008 to 2018,cancer SMR decreased in the study region(AAPC=−3.09%,P<0.001),which increased LE.The positive effect was the greatest in the 75-79 age group(0.120 years,2.90%),and the negative effect was the greatest in the 50-54 age group(-0.094 years,−2.20%).Compared to 2008,cancer CELE increased by 3.95 years,PGLEs increased by 0.32 years,and rate of life lost increased by 0.21%in 2018.Conclusions:Cancer SMR decreased in key areas of 4 provinces from 2008 to 2018.This change had a positive effect on the increase of LE.However,the rate of life lost due to cancer increased.Integrated interventions should continue to further reduce the cancer burden.展开更多
Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience...Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience-dependent mechanisms.The pruning process involves multiple molecular signals and a series of regulatory activities governing the“eat me”and“don't eat me”states.Under physiological conditions,the interaction between glial cells and neurons results in the clearance of unnecessary synapses,maintaining normal neural circuit functionality via synaptic pruning.Alterations in genetic and environmental factors can lead to imbalanced synaptic pruning,thus promoting the occurrence and development of autism spectrum disorder,schizophrenia,Alzheimer's disease,and other neurological disorders.In this review,we investigated the molecular mechanisms responsible for synaptic pruning during neural development.We focus on how synaptic pruning can regulate neural circuits and its association with neurological disorders.Furthermore,we discuss the application of emerging optical and imaging technologies to observe synaptic structure and function,as well as their potential for clinical translation.Our aim was to enhance our understanding of synaptic pruning during neural development,including the molecular basis underlying the regulation of synaptic function and the dynamic changes in synaptic density,and to investigate the potential role of these mechanisms in the pathophysiology of neurological diseases,thus providing a theoretical foundation for the treatment of neurological disorders.展开更多
Nerve trauma commonly results in chronic neuropathic pain. This is by triggering the release of proinflammatory mediators from local and invading cells that induce inflammation and nociceptive neuron hyperexcitability...Nerve trauma commonly results in chronic neuropathic pain. This is by triggering the release of proinflammatory mediators from local and invading cells that induce inflammation and nociceptive neuron hyperexcitability. Even without apparent inflammation, injury sites are associated with increased inflammatory markers. This review focuses on how it might be possible to reduce neuropathic pain by reducing inflammation. Physiologically, pain is resolved by a combination of the out-migration of pro-inflammatory cells from the injury site, the down-regulation of the genes underlying the inflammation, up-regulating genes for anti-inflammatory mediators, and reducing nociceptive neuron hyperexcitability. While various techniques reduce chronic neuropathic pain, the best are effective on < 50% of patients, no technique reliably or permanently eliminates neuropathic pain. This is because most techniques are predominantly aimed at reducing pain, not inflammation. In addition, while single factors reduce pain, increasing evidence indicates significant and longer-lasting pain relief requires multiple factors acting simultaneously. Therefore, it is not surprising that extensive data indicate that the application of platelet-rich plasma provides more significant and longer-lasting pain suppression than other techniques, although its analgesia is neither complete nor permanent. However, several case reports indicate that platelet-rich plasma can induce permanent neuropathic pain elimination when the platelet concentration is significantly increased and is applied to longer nerve lengths. This review examines the primary triggers of the development and maintenance of neuropathic pain and techniques that reduce chronic neuropathic pain. The application of plateletrich plasma holds great promise for providing complete and permanent chronic neuropathic pain elimination.展开更多
The H7 N9 viruses that emerged in China in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. The H7 N9 influenza viruses have ca...The H7 N9 viruses that emerged in China in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. The H7 N9 influenza viruses have caused five waves of human infection, with almost half of the total number of human cases(766 of 1,567) being reported in the fifth wave, raising concerns that even more human infections could occur in the sixth wave. In September 2017, an H5/H7 bivalent inactivated vaccine for chickens was introduced, and the H7 N9 virus isolation rate in poultry dropped by 93.3% after vaccination. More importantly,only three H7 N9 human cases were reported between October 1, 2017 and September 30, 2018, indicating that vaccination of poultry successfully eliminated human infection with H7 N9 virus. These facts emphasize that active control of animal disease is extremely important for zoonosis control and human health protection.展开更多
Syphilis （historically called lues） is a sexually transmitted disease （STD） caused by the spirochete bacteriumTreponema pallidum subspecies pallidum. Syphilis had many alternate names, such as the ＂great pox＂ in...Syphilis （historically called lues） is a sexually transmitted disease （STD） caused by the spirochete bacteriumTreponema pallidum subspecies pallidum. Syphilis had many alternate names, such as the ＂great pox＂ in order to distinguish it from smallpox, and was given many national attributions, such as the French pox, the English pox, and the Italian pox, due to the disease often being spread by foreign sailors and soldiers during their frequent,展开更多
Background:Lymphatic filariasis is endemic in nine of the eleven Member States of the World Health Organization South East Asia Region.This article describes the intensive interventions with the National Programme for...Background:Lymphatic filariasis is endemic in nine of the eleven Member States of the World Health Organization South East Asia Region.This article describes the intensive interventions with the National Programme for Elimination of Lymphatic Filariasis in Thailand since its launch in 2001 till the validation of its elimination in 2017.Methods:A baseline epidemiological survey was initiated in 2001 to identify both brugian and bancroftian filarial areas and delineate its endemicity.Mass drug administration(MDA)with diethylcarbamazine citrate(DEC)and albendazole(ALB)was implemented in a total of 357 implementation units(IUs)in 11 lymphatic filariasis(LF)endemic provinces.The implementing unit(IU)was a sub-village.Stop-MDA surveys were conducted in 2006 in the 11 LF endemic provinces among population over 6 years of age and children of≤6 years using immunochromatographic test(ICT)for Wuchererio bancrofti antigen and microfilariae(mf)detection for Brugia maloyi.In Narathiwat province,Stop-MDA surveys were done in 2011 using ELISA.Transmission assessment surveys(TAS)were conducted in 2012-2013,2015 and 2016-2017 among school students in the 6-7-year age-group.Surveillance of migrant populations through the national migrant health checkup were intensified in seven provinces over 2002-2017 for LF antigenaemia using ICT test cards.In four B.m oloyi endemic provinces,annual surveys to detect LF reservoir in domestic cats commenced in 1994.A 2001 survey of the chronic disease burden for LF established a register of the cumulative number of people with lymphedema/elephantiasis.Results:A total of five rounds of MDA annually were implemented over 2002-2006 in all Ills.Additional annual rounds of MDA were required in 87 Ills of Narathiwat province from 2007 to 2011 due to persistent infection.The annual national drug coverage with MDA over 2002-2012 was in the range of 68.0 to 95.4%.Stop-MDA surveys in 2006 in the 11 LF endemic provinces found nine mf positive cases in seven Ills in Narathiwat province with the highest prevalence of 0.8%(range:0.1-0.8%).In Narathiwat TAS-1,TAS-2 and TAS-3 detected below transmission threshold rates for B.m oloyi mf among antibody positive children(0.3,0.2 and 0.7%respectively).Contact tracing both all mf cases in all three TAS yielded no positive cases.Through the migrant health checkup,a total of 23477 persons were tested,showing a positive rate of 0.7%(range:0.1-2.7%)over years 2002-2017.In Narathiwat province,annual ivermectin treatment among cats commenced in 2003 resulting in a decline of mf prevalence among cats from 8.0%in 1995 to 0.8%in 2015.As of April 2011,a total of 99 lymphoedema/elephantiasis patients were registered and followed-up under 34 health facilities.Conclusions:Thailand over the years 2002 to 2011 conducted extensive MDA with high coverage rates.Through periodic and regular monitoring surveys it delineated LF transmission areas at sub-village level and demonstrated through its evaluation surveys-the Stop-MDA surveys and TAS,below transmission threshold rates that enabled its validation of LF elimination.In September 2017,World Health Organization acknowledged the Ministry of Health Thailand had eliminated lymphatic filariasis as a public health problem.展开更多
Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si...Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si alloys fabricated by laser powder-bed fusion(L-PBF).The results indicate that the eutectic Mg_(2) Si phase possesses a strong ability to reduce crack susceptibility.It can enhance the grain growth restriction factor in the initial stage of solidification and promote eutectic filling in the terminal stage of solidifica-tion.The crack-free L-PBFed Al-x Mg_(2) Si alloys(x=6 wt.%,9 wt.%,and 12 wt.%)exhibit the combination of low crack susceptibility index(CSI),superior ability for liquid filling,and grain refinement.Particularly,the L-PBFed Al-9Mg_(2) Si alloy shows improved mechanical properties(e.g.yield strength of 397 MPa and elongation of 7.3%).However,the cracks are more likely to occur in the region near the columnar grain boundaries of the L-PBFed Al-3Mg_(2) Si alloy with a large solidification range and low eutectic content for liquid filling.Correspondingly,the L-PBFed Al-3Mg_(2) Si alloy shows poor bearing capacity of mechanical properties.The precise tuning of Mg_(2) Si eutectic content can offer an innovative strategy for eliminating cracks in additively manufactured Al-Mg-Si alloy.展开更多
The hydraulic fractures induced in soft coal composite reservoirs have complex extension and energy evolution characteristics.In this study,the mechanism whereby gas outbursts can be eliminated by hydraulic fracturing...The hydraulic fractures induced in soft coal composite reservoirs have complex extension and energy evolution characteristics.In this study,the mechanism whereby gas outbursts can be eliminated by hydraulic fracturing was revealed.The combined fracturing process of a coal seam and its roof under different in situ stress and fracture spacing conditions was analysed through true triaxial physical tests and numerical simulations.The results showed that the pre-fracturing of the roof had a pressure relief effect on the coal seam,and the secondary pressure relief of the coal seam could be completed at a lower fracture initiation pressure.To ensure the continued presence of the stress shadow effect in actual projects,the fracture spacing should be maintained within the critical range influencing the fracture extension.If the vertical stress is high,a call on increasing the fracture spacing can be taken;otherwise,it must be reduced.In the early phase of fracturing,energy is mostly concentrated at the tip and surface of the fracture;however,the proportion of surface energy for subsequent fracturing is gradually reduced,and the energy is mostly used to open the formation and work on the surrounding matrix.Hydraulic fracturing creates new fractures to interconnect originally heterogeneously distributed gas zones,enabling the entire coal seam to first establish interconnected pressure equilibration,then undergo gradientcontrolled depressurization.Hydraulic fracturing can homogenize the stress field and gas pressure field in the original coal seam via communication pressure equalization and reduction decompression,reduce the elastic and extension energies,increase the minimum failure energy required for instability;and realize the elimination of gas outbursts.Our findings provide some theoretical support for the efficient development of coalbed methane and the prevention and control of dynamic gas disasters in coal mines.展开更多
Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal tract.However,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,...Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal tract.However,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,gastrointestinal dysfunction,and increased recurrence rates.When these concerns develop,traditional Chinese medicine(TCM)may have advantages.TCM is based on the concept of completeness and aims to eliminate pathogens and strengthen the body.It has the potential to prevent this condition while also boosting the rate of Helicobacter pylori eradication.This review elaborates on the mechanism of TCM treatment for HPAG based on cellular signalling pathways,which reflects the flexibility of TCM in treating diseases and the advantages of multi-level,multipathway,and multi-target treatments for HPAG.展开更多
Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfor...Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfortunately their inverse kinematics have not yet been resolved.This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics,meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships.Therefore,to break through this challenges,the huge coupling relationships are decoupled layer by layer,the kinematic parameters of middle platform are solved by combining Sylvester's elimination method,and the inverse displacements of 2(3RPS)and 2(3SPR)S-PMs are obtained subsequently.This paper not only solves the inverse kinematics of classical 2(3RPS)and 2(3SPR)S-PMs,but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF)6-DOF S-PMs and proposes a corresponding solution.展开更多
During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their el...During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.展开更多
The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-di...The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.展开更多
Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have ac...Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have achieved high human papillomavirus(HPV)vaccination coverage and implemented quality-assured cervical cancer screening programs-have successfully decreased the incidence rates to below 8 cases per 100,000 women~1.These countries are on track to reach the elimination threshold of fewer than 4 cases per 100,000 women within the next few years,as defined by the World Health Organization(WHO).展开更多
文摘The World Health Organization declared Sri Lanka a malaria eliminated country in 2016[1-3].At present,the country is in the phase of preventing the re-establishment of malaria[4].However,travelers who contract the disease overseas in malaria endemic countries continue to present a constant risk of re-establishing malaria in Sri Lanka,where malaria-transmitting mosquitos is prevalent.In this context,robust measures are being implemented in the country to prevent re-establishment of malaria and to stop travelers infected with malaria progressing into severe disease and death.
文摘Nowadays, distributing network-connected photovoltaic (PV) systems are expanded by merging a PV system and a Direct Current (DC)/Alternating Current (AC) energy converter. DC/AC conversion of PV energy is in great demand for AC applications. The supply of electrical machines and transfer energy to the distribution network is a typical case. In this work, we study and design a DC/AC energy converter using harmonic selective eliminated (HSE) method. To this end, we have combined two power stages connected in derivation. Each power stage is constituted of transistors and transformers. The connection by switching of the two rectangular waves, delivered by each of the stages, makes it possible to create a quasi-sinusoidal output voltage of the inverter. Mathematical equations based on the current-voltage characteristics of the inverter have been developed. The simulation model was validated using experimental data from a 25.2 kWp grid-coupled (PV) system, connected to Gridfit type inverters. The data were exported and implemented in programming software. A good agreement was observed and this shows all the robustness and the technical performances of the energy converter device. It emerges from this analysis that the inverter output voltage and the phase angle thus simulated are very important to control in order to orientate the transfer of the power flow from the continuous cell to cell to the alternating part. Simulated and field-testing results also show that increases in the value of the modulation factor (m) for low power output are highly significant. This study is an important tool for DC/AC inverter designers during initial planning stages. A short presentation of the design model of the inverter has been proposed in this article.
文摘The "expectations gap" signifies the differences between what the public expects from an audit and what the auditing profession prefers the audit objectives to be.Although the gap exists,it seems that the professions trust that it could be eliminated.In this paper,further evidence was provided to deny the above point by exploring the inevitability nature and the structure of the audit expectation gap.In addition,the author concludes that expectations gap cannot be eliminated;instead,the only thing can be done is to narrow down the gap.
文摘Objective:To describe the situation of measles in Sri Lanka from May to November,2023 and to define the role of virology laboratory towards case confirmation and epidemiological and genetic characterization of the outbreak.Methods:This retrospective study analyzed all samples tested for measles from 1st of May to 30th of November,2023 at National Measles Rubella Laboratory,Sri Lanka.According to the World Health Organization(WHO)algorithm,serum and oropharyngeal/nasopharyngeal swabs were tested with WHO recommended kits for anti-measles IgM and measles virus specific RNA,respectively.Selected RNA positive samples were sequenced at reference laboratory,India.Analysis of sequencing data and construction of phylogenetic tree were carried out at National Measles Rubella Laboratory.Data was analyzed using descriptive statistics.Results:Of the total 1132 serum samples and 497 oropharyngeal/nasopharyngeal swabs from 1326 patients,657(49.5%)patients were confirmed as measles by anti-measles IgM,measles virus specific RNA or both.Males(55.6%,n=365)and the age group from>20 to≤30 years(33.0%,n=217)predominated positive patients.All provinces reported measles positive cases.All samples sequenced(100%,n=42)were genotype D8 with 95.2%(n=40)bearing Victoria.Australia origin.Conclusions:We described resurgence of measles in an eliminated country,confirming the genotype to be D8,one of the two genotypes currently circulating globally.Further,the study strongly convinced the importance of a strengthened virological surveillance system in an eliminated country,despite its eliminated status.
基金Supported by Agricultural Scientific and Technologic Program of Fujian Province(2009-03)
文摘[Objective] The aim was to explore the effect of eliminated the breeding pigs with unqualified CSFV antibody on sow's reproductive performance and pig's growth performance so as to provide a scientific basis for the eliminating of the breeding pigs with unqualified CSFV antibody in large-scale pig farms.[Method] Serum samples from three scale pig farms were collected and tested with HerdChek CSFV-ELISA kit,then provided a certain scientific basis for scale pig farm to eliminate the unqualified(antibody blocking rate<50%)breeders after booster immunization.[Result ] After eliminating the breeding pigs with unqualified CSFV antibody,the average litter number of piglet in three pig farms(A,B,C)were increased by 0.29(P<0.05),0.40(P<0.01),0.39(P<0.01)respectively;the average number of survival piglets were increased by 0.54(P<0.01),0.35(P<0.01),0.62(P<0.01)respectively;the average litter number of weaned piglets were increased by 0.65(P<0.01),0.71(P<0.01),0.81(P<0.01)respectively.The difference in weight gain of piglet at 30-60 d of age was extremely significant(P<0.01),but inconspicuousness for the swine pregnancy rate,the survival rate of weaned piglet and piglet at 30-60 d of age.[Conclusion] The eliminating the breeding pigs with unqualified CSFV antibody can significantly improve the performance of breeder and piglets.
基金Sponsored by the Science Fund of Harbin City(Grant No.2005AA6CN080) and Science Found of Heilongjiang Province(Grant No.GB06B303 -3).
文摘The discoloration of Scot pine （Pinus sylvestris var. Mongolica） veneers caused by resin-eliminated treatment and the reversion of the color were studied. The result showed that the color of the veneers changed from buff to yellowish brown after the treatment of resin elimination and the discoloration of heartwood was more severe than that of sapwood; the degree of discoloration was significantly positively correlated with the medicament strength, temperature and resin-eliminated duration. The variance analysis showed the effects of those three factors on the discoloration were significant. With hydrogen peroxide （H2O2） as color reversion medicament and inorganic compound as medium of the reaction, the reversion of the color of heartwood was more inaccessible than that of sapwood; the degree of the color’s reversion was positively correlated with the H2O2 strength, temperature and treating time; the H2O2 concentration has significant effects on the discoloration. In order to reduce discoloration of Scot pine veneers, medicament of resin-eliminated used have to be at some low concentration, and the optimal concentration of H2O2 is 0.35% during the process of color’s reversion.
基金China National Key Research and Development Plan[grant number 2017YFB0504203]China Scholarship Fund[grant number 201706655028]Natural Science Foundation of Fujian Province[grant number 2017J01658].
文摘The effect of terrain shadow, including the self and cast shadows, is one ofthe main obstacles for accurate retrieval of vegetation parameters byremote sensing in rugged terrains. A shadow- eliminated vegetation index(SEVI) was developed, which was computed from only red and nearinfrared top-of-atmosphere reflectance without other heterogeneous dataand topographic correction. After introduction of the conceptual modeland feature analysis of conventional wavebands, the SEVI was constructedby ratio vegetation index (RVI), shadow vegetation index (SVI) andadjustment factor (f (Δ)). Then three methods were used to validate theSEVI accuracy in elimination of terrain shadow effects, including relativeerror analysis, correlation analysis between the cosine of solar incidenceangle (cosi) and vegetation indices, and comparison analysis between SEVIand conventional vegetation indices with topographic correction. Thevalidation results based on 532 samples showed that the SEVI relativeerrors for self and cast shadows were 4.32% and 1.51% respectively. Thecoefficient of determination between cosi and SEVI was only 0.032 and thecoefficient of variation (std/mean) for SEVI was 12.59%. The results indicatethat the proposed SEVI effectively eliminated the effect of terrain shadowsand achieved similar or better results than conventional vegetation indiceswith topographic correction.
基金Supported by The National Key Research and Development Program of China(2016YFC 1302603,2016YFC1302600).
文摘Introduction:Cancer is a major health problem in China.Integrated interventions have been implemented in key areas of Anhui,Henan,Jiangsu,and Shandong provinces with historically higher than average cancer mortality.Assessing the cancer mortality trend and its impact on life expectancy(LE)could help evaluate the effectiveness of interventions in these regions.Methods:Based on the National Cause-of-Death Surveillance,we analyzed the standardized mortality rate(SMR)of cancer,cause eliminated life expectancy(CELE),potential gains in life expectancy(PGLEs),and rate of life lost in key areas of 4 provinces from 2008 to 2018.Joinpoint program was used to compute the average annual percentage change(AAPC)of cancer mortality.Arriaga’s decomposition method was used to estimate the contribution of cancer to LE in each age group.Results:From 2008 to 2018,cancer SMR decreased in the study region(AAPC=−3.09%,P<0.001),which increased LE.The positive effect was the greatest in the 75-79 age group(0.120 years,2.90%),and the negative effect was the greatest in the 50-54 age group(-0.094 years,−2.20%).Compared to 2008,cancer CELE increased by 3.95 years,PGLEs increased by 0.32 years,and rate of life lost increased by 0.21%in 2018.Conclusions:Cancer SMR decreased in key areas of 4 provinces from 2008 to 2018.This change had a positive effect on the increase of LE.However,the rate of life lost due to cancer increased.Integrated interventions should continue to further reduce the cancer burden.
基金supported by the National Natural Science Foundation of China,No.31760290,82160688the Key Development Areas Project of Ganzhou Science and Technology,No.2022B-SF9554(all to XL)。
文摘Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience-dependent mechanisms.The pruning process involves multiple molecular signals and a series of regulatory activities governing the“eat me”and“don't eat me”states.Under physiological conditions,the interaction between glial cells and neurons results in the clearance of unnecessary synapses,maintaining normal neural circuit functionality via synaptic pruning.Alterations in genetic and environmental factors can lead to imbalanced synaptic pruning,thus promoting the occurrence and development of autism spectrum disorder,schizophrenia,Alzheimer's disease,and other neurological disorders.In this review,we investigated the molecular mechanisms responsible for synaptic pruning during neural development.We focus on how synaptic pruning can regulate neural circuits and its association with neurological disorders.Furthermore,we discuss the application of emerging optical and imaging technologies to observe synaptic structure and function,as well as their potential for clinical translation.Our aim was to enhance our understanding of synaptic pruning during neural development,including the molecular basis underlying the regulation of synaptic function and the dynamic changes in synaptic density,and to investigate the potential role of these mechanisms in the pathophysiology of neurological diseases,thus providing a theoretical foundation for the treatment of neurological disorders.
文摘Nerve trauma commonly results in chronic neuropathic pain. This is by triggering the release of proinflammatory mediators from local and invading cells that induce inflammation and nociceptive neuron hyperexcitability. Even without apparent inflammation, injury sites are associated with increased inflammatory markers. This review focuses on how it might be possible to reduce neuropathic pain by reducing inflammation. Physiologically, pain is resolved by a combination of the out-migration of pro-inflammatory cells from the injury site, the down-regulation of the genes underlying the inflammation, up-regulating genes for anti-inflammatory mediators, and reducing nociceptive neuron hyperexcitability. While various techniques reduce chronic neuropathic pain, the best are effective on < 50% of patients, no technique reliably or permanently eliminates neuropathic pain. This is because most techniques are predominantly aimed at reducing pain, not inflammation. In addition, while single factors reduce pain, increasing evidence indicates significant and longer-lasting pain relief requires multiple factors acting simultaneously. Therefore, it is not surprising that extensive data indicate that the application of platelet-rich plasma provides more significant and longer-lasting pain suppression than other techniques, although its analgesia is neither complete nor permanent. However, several case reports indicate that platelet-rich plasma can induce permanent neuropathic pain elimination when the platelet concentration is significantly increased and is applied to longer nerve lengths. This review examines the primary triggers of the development and maintenance of neuropathic pain and techniques that reduce chronic neuropathic pain. The application of plateletrich plasma holds great promise for providing complete and permanent chronic neuropathic pain elimination.
基金supported by the National Key R&D Program of China (2016YFD0500201, 2016YFD0500203)the National Natural Science Foundation of China (31521005)+1 种基金the China Agriculture Research System (CARS-41-G12)the US NIH CEIRS contract HHSN272201400004C
文摘The H7 N9 viruses that emerged in China in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. The H7 N9 influenza viruses have caused five waves of human infection, with almost half of the total number of human cases(766 of 1,567) being reported in the fifth wave, raising concerns that even more human infections could occur in the sixth wave. In September 2017, an H5/H7 bivalent inactivated vaccine for chickens was introduced, and the H7 N9 virus isolation rate in poultry dropped by 93.3% after vaccination. More importantly,only three H7 N9 human cases were reported between October 1, 2017 and September 30, 2018, indicating that vaccination of poultry successfully eliminated human infection with H7 N9 virus. These facts emphasize that active control of animal disease is extremely important for zoonosis control and human health protection.
文摘Syphilis （historically called lues） is a sexually transmitted disease （STD） caused by the spirochete bacteriumTreponema pallidum subspecies pallidum. Syphilis had many alternate names, such as the ＂great pox＂ in order to distinguish it from smallpox, and was given many national attributions, such as the French pox, the English pox, and the Italian pox, due to the disease often being spread by foreign sailors and soldiers during their frequent,
文摘Background:Lymphatic filariasis is endemic in nine of the eleven Member States of the World Health Organization South East Asia Region.This article describes the intensive interventions with the National Programme for Elimination of Lymphatic Filariasis in Thailand since its launch in 2001 till the validation of its elimination in 2017.Methods:A baseline epidemiological survey was initiated in 2001 to identify both brugian and bancroftian filarial areas and delineate its endemicity.Mass drug administration(MDA)with diethylcarbamazine citrate(DEC)and albendazole(ALB)was implemented in a total of 357 implementation units(IUs)in 11 lymphatic filariasis(LF)endemic provinces.The implementing unit(IU)was a sub-village.Stop-MDA surveys were conducted in 2006 in the 11 LF endemic provinces among population over 6 years of age and children of≤6 years using immunochromatographic test(ICT)for Wuchererio bancrofti antigen and microfilariae(mf)detection for Brugia maloyi.In Narathiwat province,Stop-MDA surveys were done in 2011 using ELISA.Transmission assessment surveys(TAS)were conducted in 2012-2013,2015 and 2016-2017 among school students in the 6-7-year age-group.Surveillance of migrant populations through the national migrant health checkup were intensified in seven provinces over 2002-2017 for LF antigenaemia using ICT test cards.In four B.m oloyi endemic provinces,annual surveys to detect LF reservoir in domestic cats commenced in 1994.A 2001 survey of the chronic disease burden for LF established a register of the cumulative number of people with lymphedema/elephantiasis.Results:A total of five rounds of MDA annually were implemented over 2002-2006 in all Ills.Additional annual rounds of MDA were required in 87 Ills of Narathiwat province from 2007 to 2011 due to persistent infection.The annual national drug coverage with MDA over 2002-2012 was in the range of 68.0 to 95.4%.Stop-MDA surveys in 2006 in the 11 LF endemic provinces found nine mf positive cases in seven Ills in Narathiwat province with the highest prevalence of 0.8%(range:0.1-0.8%).In Narathiwat TAS-1,TAS-2 and TAS-3 detected below transmission threshold rates for B.m oloyi mf among antibody positive children(0.3,0.2 and 0.7%respectively).Contact tracing both all mf cases in all three TAS yielded no positive cases.Through the migrant health checkup,a total of 23477 persons were tested,showing a positive rate of 0.7%(range:0.1-2.7%)over years 2002-2017.In Narathiwat province,annual ivermectin treatment among cats commenced in 2003 resulting in a decline of mf prevalence among cats from 8.0%in 1995 to 0.8%in 2015.As of April 2011,a total of 99 lymphoedema/elephantiasis patients were registered and followed-up under 34 health facilities.Conclusions:Thailand over the years 2002 to 2011 conducted extensive MDA with high coverage rates.Through periodic and regular monitoring surveys it delineated LF transmission areas at sub-village level and demonstrated through its evaluation surveys-the Stop-MDA surveys and TAS,below transmission threshold rates that enabled its validation of LF elimination.In September 2017,World Health Organization acknowledged the Ministry of Health Thailand had eliminated lymphatic filariasis as a public health problem.
基金financially supported by the National Natural Science Foundation of China(Grant No.52071343)the Leading Innovation and Entrepreneurship Team of Zhejiang Province-Automotive Light Alloy Innovation Team(No.2022R01018).
文摘Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si alloys fabricated by laser powder-bed fusion(L-PBF).The results indicate that the eutectic Mg_(2) Si phase possesses a strong ability to reduce crack susceptibility.It can enhance the grain growth restriction factor in the initial stage of solidification and promote eutectic filling in the terminal stage of solidifica-tion.The crack-free L-PBFed Al-x Mg_(2) Si alloys(x=6 wt.%,9 wt.%,and 12 wt.%)exhibit the combination of low crack susceptibility index(CSI),superior ability for liquid filling,and grain refinement.Particularly,the L-PBFed Al-9Mg_(2) Si alloy shows improved mechanical properties(e.g.yield strength of 397 MPa and elongation of 7.3%).However,the cracks are more likely to occur in the region near the columnar grain boundaries of the L-PBFed Al-3Mg_(2) Si alloy with a large solidification range and low eutectic content for liquid filling.Correspondingly,the L-PBFed Al-3Mg_(2) Si alloy shows poor bearing capacity of mechanical properties.The precise tuning of Mg_(2) Si eutectic content can offer an innovative strategy for eliminating cracks in additively manufactured Al-Mg-Si alloy.
基金financially supported by the National Key R&D Program(Nos.2023YFC3009000 and 2023YFC3006804)the National Natural Science Foundation of China(Nos.52130409,52121003,51874314,and 52274190).
文摘The hydraulic fractures induced in soft coal composite reservoirs have complex extension and energy evolution characteristics.In this study,the mechanism whereby gas outbursts can be eliminated by hydraulic fracturing was revealed.The combined fracturing process of a coal seam and its roof under different in situ stress and fracture spacing conditions was analysed through true triaxial physical tests and numerical simulations.The results showed that the pre-fracturing of the roof had a pressure relief effect on the coal seam,and the secondary pressure relief of the coal seam could be completed at a lower fracture initiation pressure.To ensure the continued presence of the stress shadow effect in actual projects,the fracture spacing should be maintained within the critical range influencing the fracture extension.If the vertical stress is high,a call on increasing the fracture spacing can be taken;otherwise,it must be reduced.In the early phase of fracturing,energy is mostly concentrated at the tip and surface of the fracture;however,the proportion of surface energy for subsequent fracturing is gradually reduced,and the energy is mostly used to open the formation and work on the surrounding matrix.Hydraulic fracturing creates new fractures to interconnect originally heterogeneously distributed gas zones,enabling the entire coal seam to first establish interconnected pressure equilibration,then undergo gradientcontrolled depressurization.Hydraulic fracturing can homogenize the stress field and gas pressure field in the original coal seam via communication pressure equalization and reduction decompression,reduce the elastic and extension energies,increase the minimum failure energy required for instability;and realize the elimination of gas outbursts.Our findings provide some theoretical support for the efficient development of coalbed methane and the prevention and control of dynamic gas disasters in coal mines.
基金Supported by National Natural Science Foundation of China,No.82374323and Hunan Graduate Research Innovation Project,No.2023CX15.
文摘Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal tract.However,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,gastrointestinal dysfunction,and increased recurrence rates.When these concerns develop,traditional Chinese medicine(TCM)may have advantages.TCM is based on the concept of completeness and aims to eliminate pathogens and strengthen the body.It has the potential to prevent this condition while also boosting the rate of Helicobacter pylori eradication.This review elaborates on the mechanism of TCM treatment for HPAG based on cellular signalling pathways,which reflects the flexibility of TCM in treating diseases and the advantages of multi-level,multipathway,and multi-target treatments for HPAG.
基金Supported by National Natural Science Foundation of China(Grant No.52275033)National Natural Science Youth Foundation of China(Grant No.52205033)Hebei Provincial Natural Science Foundation of China(Grant No.E2021203019)。
文摘Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfortunately their inverse kinematics have not yet been resolved.This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics,meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships.Therefore,to break through this challenges,the huge coupling relationships are decoupled layer by layer,the kinematic parameters of middle platform are solved by combining Sylvester's elimination method,and the inverse displacements of 2(3RPS)and 2(3SPR)S-PMs are obtained subsequently.This paper not only solves the inverse kinematics of classical 2(3RPS)and 2(3SPR)S-PMs,but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF)6-DOF S-PMs and proposes a corresponding solution.
基金supported by Catalan Government,Nos.2014SGR344(to JT),2017SGR704(to JT),2021SGR01214(to MAL)MCIN/AEI/10.13039/501100011033/by“ERDF A way of making Europe,”Nos.SAF2015-67143(to JT),PID2019-106332GB-I00(to JT and MAL)and PID2022-141252NB-I00(to MAL).
文摘During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.
文摘The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.
文摘Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have achieved high human papillomavirus(HPV)vaccination coverage and implemented quality-assured cervical cancer screening programs-have successfully decreased the incidence rates to below 8 cases per 100,000 women~1.These countries are on track to reach the elimination threshold of fewer than 4 cases per 100,000 women within the next few years,as defined by the World Health Organization(WHO).
