Chronic atrophic gastritis(CAG)is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa,reducing the stomach's ability to secrete gastric juice and pepsi...Chronic atrophic gastritis(CAG)is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa,reducing the stomach's ability to secrete gastric juice and pepsin,and interfering with its normal physiological function.Multiple pathogenic factors contribute to CAG incidence,the most common being Helicobacter pylori infection and the immune reactions resulting from gastric autoimmunity.Furthermore,CAG has a broad spectrum of clinical manifestations,including gastroenterology and extraintestinal symptoms and signs,such as hematology,neurology,and oncology.Therefore,the initial CAG evaluation should involve the examination of clinical and serological indicators,as well as diagnosis confirmation via gastroscopy and histopathology if necessary.Depending on the severity and scope of atrophy affecting the gastric mucosa,a histologic staging system(Operative Link for Gastritis Assessment or Operative Link on Gastritis intestinal metaplasia)could also be employed.Moreover,chronic gastritis has a higher risk of progressing to gastric cancer(GC).In this regard,early diagnosis,treatment,and regular testing could reduce the risk of GC in CAG patients.However,the optimal interval for endoscopic monitoring in CAG patients remains uncertain,and it should ideally be tailored based on individual risk evaluations and shared decision-making processes.Although there have been many reports on CAG,the precise etiology and histopathological features of the disease,as well as the diagnosis of CAG patients,are yet to be fully elucidated.Consequently,this review offers a detailed account of CAG,including its key clinical aspects,aiming to enhance the overall understanding of the disease.展开更多
The longitudinal study sought to examine the dynamic development of cognitive skills for reading among elementary-level students in China's Mainland. Two groups of students in first (n=164, mean age=6.65 years at...The longitudinal study sought to examine the dynamic development of cognitive skills for reading among elementary-level students in China's Mainland. Two groups of students in first (n=164, mean age=6.65 years at first test) and second grade (n=202, mean age=7.73 years at first test) were followed on orthographic awareness, morphological awareness and rapid automatized naming (RAN) for two years. The children exhibited significant improvement in orthographic awareness, morphological awareness and RAN from grades 1 to 4. More importantly, to the orthographic and morphological awareness, while the children took a leap from grade 1 to 2 and grade 3 to 4, the progress developed at relatively slow rates from grade 2 to 3. In order to assure children's development of orthographic and morphological awareness, evidence-based orthographically and morphologically enhanced instruction is needed for Chinese children in the early elementary years, especially for those at the stage from grade 2 to 3.展开更多
Until now,seismic-isolation structures have not yet been applied in the railway field.The reason is that though a seismic-isolation structure can reduce the inertial force to the structure,the energy absorption causes...Until now,seismic-isolation structures have not yet been applied in the railway field.The reason is that though a seismic-isolation structure can reduce the inertial force to the structure,the energy absorption causes big response displacement on the structure,which adversely effects the running safety of the trains supported by the structure.In this paper,a methodology for seismic running safety assessment is introduced,and a new type of seismic-isolation foundation is proposed,which can convert the seismic response displacement in the lateral direction of track to the longitudinal direction that has a less adverse effect on the running safety of the train.The isolation foundation is composed of FPS(Friction Pendulum System)slider,concave plate and guide ditch.Moreover,through model experiments and 3D numerical simulation,it is verified that the proposed foundation can keep both the effects of the seismic isolation and the running safety of the train during an earthquake.展开更多
Enantioselective cis-dihydroxylation of alkenes represents an ideal route to synthesize enantioenriched syn-2,3-dihydroxy esters that are important structural motifs in numerous biologically and pharmaceutically relev...Enantioselective cis-dihydroxylation of alkenes represents an ideal route to synthesize enantioenriched syn-2,3-dihydroxy esters that are important structural motifs in numerous biologically and pharmaceutically relevant molecules.Bioinspired nonheme iron-catalyzed enantioselective cis-dihydroxylation meets the requirement of the modern synthetic chemistry from the atomic economy,green chemistry,and sustainable development perspectives.However,nonheme iron-catalyzed enantioselective cis-dihydroxylation is much underdeveloped because of the formidable challenges of controlling chemo-and enantioselectivities and product selectivity caused by the competitive epoxidation,cis-dihydroxylation,and overoxidation reactions.Herein,we disclose the fabrication of a biologically inspired nonheme iron complex-catalyzed enantioselective cis-dihydroxylation of multisubstituted acrylates using hydrogen peroxide(H_(2)O_(2))as the terminal oxidant by controlling the non-ligating or weakly ligating counterions of iron(Ⅱ)complexes,demonstrating a dramatic counteranion effect on the enantioselective cisdihydroxylation of olefins by H_(2)O_(2) catalyzed by nonheme iron complexes.A range of structurally disparate alkenes were transformed to the corresponding syn-2,3-dihydroxy esters in practically useful yields with exquisite chemo-and enantioselectivities(up to 99% ee).Given the mild and benign nature of this biologically inspired oxidation system as well as the ubiquity and synthetic utility of enantioenriched syn-2,3-dihydroxy esters as pharmaceuticals candidates and natural products,we expect that this strategy could serve as a promising complement to the well-known Sharpless asymmetric dihydroxylation,which is the chemical reaction of an alkene with OsO_(4) to produce a vicinal diol.展开更多
文摘Chronic atrophic gastritis(CAG)is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa,reducing the stomach's ability to secrete gastric juice and pepsin,and interfering with its normal physiological function.Multiple pathogenic factors contribute to CAG incidence,the most common being Helicobacter pylori infection and the immune reactions resulting from gastric autoimmunity.Furthermore,CAG has a broad spectrum of clinical manifestations,including gastroenterology and extraintestinal symptoms and signs,such as hematology,neurology,and oncology.Therefore,the initial CAG evaluation should involve the examination of clinical and serological indicators,as well as diagnosis confirmation via gastroscopy and histopathology if necessary.Depending on the severity and scope of atrophy affecting the gastric mucosa,a histologic staging system(Operative Link for Gastritis Assessment or Operative Link on Gastritis intestinal metaplasia)could also be employed.Moreover,chronic gastritis has a higher risk of progressing to gastric cancer(GC).In this regard,early diagnosis,treatment,and regular testing could reduce the risk of GC in CAG patients.However,the optimal interval for endoscopic monitoring in CAG patients remains uncertain,and it should ideally be tailored based on individual risk evaluations and shared decision-making processes.Although there have been many reports on CAG,the precise etiology and histopathological features of the disease,as well as the diagnosis of CAG patients,are yet to be fully elucidated.Consequently,this review offers a detailed account of CAG,including its key clinical aspects,aiming to enhance the overall understanding of the disease.
文摘The longitudinal study sought to examine the dynamic development of cognitive skills for reading among elementary-level students in China's Mainland. Two groups of students in first (n=164, mean age=6.65 years at first test) and second grade (n=202, mean age=7.73 years at first test) were followed on orthographic awareness, morphological awareness and rapid automatized naming (RAN) for two years. The children exhibited significant improvement in orthographic awareness, morphological awareness and RAN from grades 1 to 4. More importantly, to the orthographic and morphological awareness, while the children took a leap from grade 1 to 2 and grade 3 to 4, the progress developed at relatively slow rates from grade 2 to 3. In order to assure children's development of orthographic and morphological awareness, evidence-based orthographically and morphologically enhanced instruction is needed for Chinese children in the early elementary years, especially for those at the stage from grade 2 to 3.
文摘Until now,seismic-isolation structures have not yet been applied in the railway field.The reason is that though a seismic-isolation structure can reduce the inertial force to the structure,the energy absorption causes big response displacement on the structure,which adversely effects the running safety of the trains supported by the structure.In this paper,a methodology for seismic running safety assessment is introduced,and a new type of seismic-isolation foundation is proposed,which can convert the seismic response displacement in the lateral direction of track to the longitudinal direction that has a less adverse effect on the running safety of the train.The isolation foundation is composed of FPS(Friction Pendulum System)slider,concave plate and guide ditch.Moreover,through model experiments and 3D numerical simulation,it is verified that the proposed foundation can keep both the effects of the seismic isolation and the running safety of the train during an earthquake.
基金the National Natural Science Foundation of China(no.21771087 to B.W and no.21703080 to J.C)the NSF of Shandong Province(no.ZR2020YQ10 to B.W)+1 种基金Taishan Scholar Program of Shandong Province(no.tsqn201812078 to B.W.)the NRF of Korea(no.NRF-2021R1A3B1076539 to W.N.and no.NRF-2020R1I1A1A01074630 to Y.-M.L.).
文摘Enantioselective cis-dihydroxylation of alkenes represents an ideal route to synthesize enantioenriched syn-2,3-dihydroxy esters that are important structural motifs in numerous biologically and pharmaceutically relevant molecules.Bioinspired nonheme iron-catalyzed enantioselective cis-dihydroxylation meets the requirement of the modern synthetic chemistry from the atomic economy,green chemistry,and sustainable development perspectives.However,nonheme iron-catalyzed enantioselective cis-dihydroxylation is much underdeveloped because of the formidable challenges of controlling chemo-and enantioselectivities and product selectivity caused by the competitive epoxidation,cis-dihydroxylation,and overoxidation reactions.Herein,we disclose the fabrication of a biologically inspired nonheme iron complex-catalyzed enantioselective cis-dihydroxylation of multisubstituted acrylates using hydrogen peroxide(H_(2)O_(2))as the terminal oxidant by controlling the non-ligating or weakly ligating counterions of iron(Ⅱ)complexes,demonstrating a dramatic counteranion effect on the enantioselective cisdihydroxylation of olefins by H_(2)O_(2) catalyzed by nonheme iron complexes.A range of structurally disparate alkenes were transformed to the corresponding syn-2,3-dihydroxy esters in practically useful yields with exquisite chemo-and enantioselectivities(up to 99% ee).Given the mild and benign nature of this biologically inspired oxidation system as well as the ubiquity and synthetic utility of enantioenriched syn-2,3-dihydroxy esters as pharmaceuticals candidates and natural products,we expect that this strategy could serve as a promising complement to the well-known Sharpless asymmetric dihydroxylation,which is the chemical reaction of an alkene with OsO_(4) to produce a vicinal diol.