Facile access to β-hydroxyl ketones via a cobalt-catalyzed ring-opening/hydroxylation cascade of cyclopropanols

A cobalt-catalyzed ring-opening/hydroxylation cascade of highly strained cyclopropanols has been developed for the first time. The reaction was conducted under open-air atmosphere to afford a broad series of structurally diverse β-hydroxy ketones in moderate to good yields with high regioselectivity.The protocol features mild reaction conditions, simple operation, high-functional-group tolerance, facile scalability, and heterocycle compatibility.

Protecting the gains of malaria elimination in China

Background About half of the world's population risks contracting malaria,which despite the effective treatments available globally,remains a life-threatening affliction,particularly for the poorest and most vulnerable populations.To raise awareness,advocacy,and action towards defeating the disease,which was responsible for approximately 228 million debilitating infections and 405000 deaths at last count in 2018,the international community has,since 2008,commemorated World Malaria Day on 25 April.Events all over the world have provided opportunities for malaria affected countries to learn from each other's experiences and support each other's efforts.Likewise,it has been an occasion for development partners across all countries to showcase their efforts against malaria,reflect on successes,and assess the challenges ahead.This year the World Malaria Day takes its theme from the pan-African campaign,first launched in Senegal,known as"Zero palu!Je m'engage"or"Zero Malaria Starts with Me".

An operational happens-before memory model

Happens-before memory model （HMM） is used as the basis of Java memory model （JMM）. Although HMM itself is simple, some complex axioms have to be introduced in JMM to prevent the causality loop, which causes absurd out-of-thin-air reads that may break the type safety and se- curity guarantee of Java. The resulting JMM is complex and difficult to understand. It also has many anti-intuitive behav- iors, as demonstrated by the ＂ugly examples＂ by Aspinall and ~ev6~ [1]. Furthermore, HMM （and JMM） specifies only what execution traces are acceptable, but says nothing about how these traces are generated. This gap makes it difficult for static reasoning about programs. In this paper we present OHMM, an operational variation of HMM. The model is specified by giving an operational semantics to a language running on an abstract machine de- signed to simulate HMM. Thanks to its generative nature, the model naturally prevents out-of-thin-air reads. On the other hand, it uses a novel replay mechanism to allow instruc- tions to be executed multiple times, which can be used to model many useful speculations and optimization. The model is weaker than JMM for lockless programs, thus can accom- modate more optimization, such as the reordering of inde- pendent memory accesses that is not valid in JMM. Program behaviors are more natural in this model than in JMM, and many of the anti-intuitive examples in JMM are no longer valid here. We hope OHMM can serve as the basis for new memory models for Java-like languages.

A temporal programming model with atomic blocks based on projection temporal logic

Atomic blocks, a high-level language construct that allows programmers to explicitly specify the atomicity of operations without worrying about the implementations, are a promising approach that simplifies concurrent programming. On the other hand, temporal logic is a successful model in logic programming and concurrency verification, but none of existing temporal programming models supports concurrent programming with atomic blocks yet. In this paper, we propose a temporal programming model （αPTL） which extends the projection temporal logic （PTL） to support concurrent programming with atomic blocks. The novel construct that formulates atomic execution of code blocks, which we call atomic interval formulas, is always interpreted over two consecutive states, with the internal states of the block being abstracted away. We show that the framing mechanism in projection temporal logic also works in the new model, which consequently supports our development of an executive language. The language supports concurrency by introducing a loose interleaving semantics which tracks only the mutual exclusion between atomic blocks. We demonstrate the usage of αPTL by modeling and verifying both the fine-grained and coarse-grained concurrency.

A relatively high zoonotic trematode prevalence in Orientogalba ollula and the developmental characteristics of isolated trematodes by experimental infection in the animal model

Background:Food-borne parasitic diseases decrease food safety and threaten public health.The snail species is an intermediate host for numerous human parasitic trematodes.Orientogalba ollula has been reported as intermediate hosts of many zoonotic trematodes.Here,we investigated the prevalence of zoonotic trematodes withinO.ollula in Guangxi,China,and assessed their zoonotic potential.Methods:Snails were collected from 54 sites in 9 cities throughout Guangxi.The snail and trematode larvae species were determined by combining morphological characteristics and molecular markers.The trematodes prevalence and constituent ratio were calculated and compared among different habitat environments.Phylogenetic trees of the trematode species were constructed using the neighbor-joining method with nuclear internal transcribed spacer 2(ITS2)sequences.The developmental cycles of the isolated trematodes were examined by experimental infection in ducks.The developmental characteristics ofEchinostoma revolutum was recorded by dissecting infected ducklings from 1-day post infection(dpi)to 10 dpi.Results:The overall prevalence of trematode larvae was 22.1%(1818/8238)inO.ollula from 11 sample sites.Morphological together with molecular identification,showed thatE.revolutum,Australapatemon sp.,Hypoderaeum conoideum,Pharyngostomum cordatum,andEchinostoma sp.parasitizedO.ollula,with the highest infection rate ofE.revolutum(13.0%).However,noFasciola larvae were detected.The trematodes prevalence and constituent ratio varied in two sub-biotypes(P<0.01).A neighbor-joining tree analysis of ITS2 sequences resulted in distinct monophyletic clades supported by sequences from isolated larvae with high bootstrap values.Ducklings exposed toO.ollula infected withEchinostoma sp.,E.revolutum,andH.conoideum larvae were successfully infected.The animal model forEchinostoma revolutum was successfully established.E.revolutum matured from larvae to adult at 10 dpi in the intestine of the duck,and the developmental characteristics ofE.revolutum were characterized by the maturation of the reproductive and digestive organs at 6-8 dpi.Conclusions:This study revealed a high prevalence of zoonotic trematodes inO.ollula from Guangxi,China.Existing trematodes infection in animals and human clinical cases,coupled with the wide geographical distribution ofO.ollula,necessitate further evaluations of the potential risk of spillover of zoonotic infection from animal to human and vice versa.

Surveillance Progress for Crucial Vector-Borne Parasitic Diseases in China

China has achieved significant progress in controlling parasitic diseases through extensive campaigns over the last seven decades.In 2015,the criteria for schistosomiasis transmission control were met nationwide(1),and no indigenous malaria cases have been reported in China since 2017(2).Moreover,the number of areas with endemic visceral leishmaniasis has been markedly reduced from 16 to 7 provincial-level administrative divisions(PLADs)(3).

Apios americana Medik flower extract protects high-glucose-treated hepatocytes and Caenorhabditis elegans

Type 2 diabetes(T2D)is a chronic metabolic disease related to glucose metabolism disorders.Increasing evidences indicate that flavonoids obtained from plants have beneficial effects on T2D.Apios americana Medik,originally cultivated in North America,is rich in flavonoids.In this study,A.americana flower extract(AFE)was purified and flavonoids were identified.The beneficial effects of AFE on glucose metabolism disorders were investigated.Results showed that AFE protected hepatic cells from oxidative stress caused by hyperglycemia and increased glucose consumption and glucose uptake.The AKT pathway was involved in AFE-mediated hypoglycemic action in LO2 cells,accompanied by phosphorylation of FoxO1,Gsk-3βand AMPK.In vivo,AFE protected Caenorhabditis elegans(C.elegans)from oxidative stress under hyperglycemia and restored the expressions of PMK-1 and SKN-1.Furthermore,AFE decreased excessive glucose and lipid accumulation and extended the lifespans of high glucose(HG)treated C.elegans.AFE might be beneficial to decrease glucose metabolism disorders and T2D.

Malaria Elimination in China and Sustainability Concerns in the Post-elimination Stage

The World Health Organization(WHO)certified China as officially malaria-free on June 30,2021.Looking back at the public health history in China,malaria elimination has been a product of complex social engineering.Here,we summarized our experience and lessons,and found that malaria control and elimination in China is mainly attributed to governmental leadership,consistent efforts,technological innovations,and adaptive approaches.We also raised that vigilance should focus on imported cases through strengthening surveillance and response systems in order to prevent any re-establishment of transmission after elimination.China should continue to maintain its laboratory,clinical and field epidemiology capabilities.Continuous policy and financial support,multi-sectoral cooperation,and innovative strategies and approaches will remain essential.By integrating these,a malaria-free status can become sustainable.