The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phen...The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ) to give dichlorobisaryltin(Ⅳ).The ~1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.展开更多
A series of new Schiff base type macrocyclic crown ethers containing naphthalene ring were synthesized from 2,2'-di(o-formylnaphthoxy) ethyl ether or 1,2-di(o-formylnaphthoxy) ethane and four appropriate diamines....A series of new Schiff base type macrocyclic crown ethers containing naphthalene ring were synthesized from 2,2'-di(o-formylnaphthoxy) ethyl ether or 1,2-di(o-formylnaphthoxy) ethane and four appropriate diamines. The chemical structures of the new compounds were characterized by elemental analysis, infrared spectra, nuclear magnetic resonance spectra and mass spectrometry.展开更多
^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination vi...^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination via a four-membered ring.For the series of XC_6H_4CH=NC_6H_3-2-HgCl-4-CH_3(X is a para-or mera-substituent),there is a good linear correlation between δ^(199)Hg and Hammett's o constants.The influence of substituents of C-pheny1 ring on the δ ^(199)Hg can be explained in terms of the intramolecular N→Hg coordination.展开更多
In the original publication,mistakenly first and corresponding affiliation is given as:Thermoelectricity Technology Center,Hangzhou Dahe Thermo-Magnetics Co.Ltd,Hangzhou 310053,ChinaThe correct first and corresponding...In the original publication,mistakenly first and corresponding affiliation is given as:Thermoelectricity Technology Center,Hangzhou Dahe Thermo-Magnetics Co.Ltd,Hangzhou 310053,ChinaThe correct first and corresponding affiliation is:State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China.展开更多
Eight bis-,two tris-and two mono-crown ethers of Schiff base type have been pre- parcd by the reaction of 4'-formylbenzo-15-crown-5 with diamincs.Conductivity measurements show that the bis-crown ethers form 1:1 c...Eight bis-,two tris-and two mono-crown ethers of Schiff base type have been pre- parcd by the reaction of 4'-formylbenzo-15-crown-5 with diamincs.Conductivity measurements show that the bis-crown ethers form 1:1 complexes(crown cther unit:metal ion)with sodium ion and 2:1 complexes with potassium,rubidium and ammonium ion,respectively.展开更多
p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel c...p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel cis-p-menthane type Schiff base derivatives were designed and synthesized. All target products were easily available novel compounds and characterized by FT-IR,^1H NMR,^13 C NMR and ESI＋-MS. Their pre-emergence herbicidal activities against annual ryegrass were evaluated. The bioassays indicated that most of the target compounds displayed excellent herbicidal activities in pre-emergence treatment.展开更多
Objective The Yubei area is located in the mid-east Maigaiti slope of southwestern Tarim Basin, China, with an exploration history of several years. Recent exploration has preliminarily indicated that the Ordovician ...Objective The Yubei area is located in the mid-east Maigaiti slope of southwestern Tarim Basin, China, with an exploration history of several years. Recent exploration has preliminarily indicated that the Ordovician carbonate formations in this area have some oil and gas potential. Carbonate microfacies provides material basis for reservoir development, seal formation and hydrocarbon generation. Therefore, this work utilized the standard microfacies （SMF） types to study the microfacies of the Ordovician formations in the Yubei area in order to provide theoretical basis for the next exploration.展开更多
Polyesters consisting of substituted aromatic type Schiff base mesogenic unit andpolymethylene spacers were synthesized and their thermal transitions and liquid crystallineproperties were studied. The liquid crystalli...Polyesters consisting of substituted aromatic type Schiff base mesogenic unit andpolymethylene spacers were synthesized and their thermal transitions and liquid crystallineproperties were studied. The liquid crystalline behaviour has been characterized by differentialscanning calorimetry (DSC) and optical polarizing microscopy. Structural broadening bysubstitution of methoxy group in 2, 2' positions of the mesogenic core produce polymers withlower transition temperatures. Polymers synthesized from ortho and meta substituted phenylenediamine did not form a liquid crystal phase.展开更多
The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base edit...The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.展开更多
The influences of the ratio of the radius of atom A（rA） to radius of atom B（rB）, electronegativity and electron number were discussed on the Laves phase formation and the characteristics of Zr-based AB2 type hydro...The influences of the ratio of the radius of atom A（rA） to radius of atom B（rB）, electronegativity and electron number were discussed on the Laves phase formation and the characteristics of Zr-based AB2 type hydrogen storage alloy. An enthalpy model of Zr-based AB2 alloy was obtained from known data and twelve Zr-based alloys were designed to test the model. The results show that the predicted values are in good agreement with the experimental values. The model can be used for predicting enthalpy values of Zr-based hydrogen storage alloys and settles a foundation for experiments.展开更多
Magnetic field induced entropy change was investigated for La-Fe based NaZn13-type compounds with magnetic first-order phase transition. In view of magnetic refrigeration at room temperature, the developing of the mat...Magnetic field induced entropy change was investigated for La-Fe based NaZn13-type compounds with magnetic first-order phase transition. In view of magnetic refrigeration at room temperature, the developing of the materials and the understanding of the entropy change were., reviewed. For La-Fe-Si compounds, the entropy change about 29 J·kg^- 1·K^-1 was obtained at 190 K under the magnetic field of 5 T.While a large entropy change of about 15 J·kg^-1·K^-1 near room temperature under 5 T can be obtained by the substitution of Co for Fe in the compounds. It is found that the entropy change is mainly composed of that contributed from magnetic ordering and crystal lattice. The large entropy change consumed by lattice contribution is mainly due to the magnetic ordering one.展开更多
Knowledge-based scoring functions have been widely used for protein structure prediction, protein-small molecule, and protein-nucleic acid interactions, in which one critical step is to find an appropriate representat...Knowledge-based scoring functions have been widely used for protein structure prediction, protein-small molecule, and protein-nucleic acid interactions, in which one critical step is to find an appropriate representation of protein structures. A key issue is to determine the minimal protein representations, which is important not only for developing of scoring func- tions but also for understanding the physics of protein folding. Despite significant progresses in simplifying residues into alphabets, few studies have been done to address the optimal number of atom types for proteins. Here, we have investigated the atom typing issue by classifying the 167 heavy atoms of proteins through 11 schemes with 1 to 20 atom types based on their physicochemical and functional environments. For each atom typing scheme, a statistical mechanics-based iterative method was used to extract atomic distance-dependent potentials from protein structures. The atomic distance-dependent pair potentials for different schemes were illustrated by several typical atom pairs with different physicochemical proper- ties. The derived potentials were also evaluated on a high-resolution test set of 148 diverse proteins for native structure recognition. It was found that there was a crossover around the scheme of four atom types in terms of the success rate as a function of the number of atom types, which means that four atom types may be used when investigating the basic folding mechanism of proteins. However, it was revealed by a close examination of typical potentials that 14 atom types were needed to describe the protein interactions at atomic level. The present study will be beneficial for the development of protein related scoring functions and the understanding of folding mechanisms.展开更多
Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the cor...Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the corresponding products in high yields.展开更多
From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn（OAc）2.2H20 in the molar ratio of 1：1 or 1：2, the mononuclear [Zn（L）（H2O）] （1） or binuclear [Zn2（L）（OAc）2（H2O）] （2） are o...From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn（OAc）2.2H20 in the molar ratio of 1：1 or 1：2, the mononuclear [Zn（L）（H2O）] （1） or binuclear [Zn2（L）（OAc）2（H2O）] （2） are obtained, respectively. For both complexes 1 and 2, the unsaturated five-coordinate coordination environment to the catalytic active centers （Zn2＋ ions） permits the monomer insertion for the effective solution copolymerization of cyclohexene oxide and maleic anhydride. All the solution copolymerizations afford poly（ester-co-ether）s, while lower catalyst and co-catalyst concentrations are helpful for the formation of alternating polyester. Of the three co-catalysts, 4-（dimethylamino）pyridine is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers.展开更多
The purpose of this study is to explore whether it is worthwhile to launch a routine diabetic retinopathy (DR) screening for blindness pre-vention among Chinese type 2 diabetes from different perspective based on the ...The purpose of this study is to explore whether it is worthwhile to launch a routine diabetic retinopathy (DR) screening for blindness pre-vention among Chinese type 2 diabetes from different perspective based on the popula-tion-based study in Kinmen, Taiwan. A total of 971 community dwelling adults previously di-agnosed with type 2 diabetes in 1991-1993 un-derwent DR screening in 1999-2002 by a panel of ophthalmologists using on-site indirect oph-thalmoscopy and 45-degree color fundus retinal photographs. The cost-benefit analysis is used to evaluate the DR screening. In terms of bene-fit-cost ratio, the different screening programs for DR could save New Taiwan Dollars (NTD) from 14.38 to 36.83 in discounted costs for each dollar incurred in different screening years from the societal viewpoint for Taiwan and save NTD from 0.81 to 1.80 in different screening years from health care payer’s perspective. The av-erage estimate of willingness-to-pay to translate into benefit yields NTD from 937.8 to 4,689 be- nefits per case due to DR screening in different screening years during 10-year follow-up. The net present value of the DR screening were NTD from -167,318 to -307,251.2 in different screening years. In conclusion, it is worthwhile to initial a routine DR screening of Chinese type 2 diabetes for blindness prevention from the societal per-spective but not from consumer decision based on the willingness-to-pay perspective.展开更多
This prospective study was designed to examine the combined influence of insulin resistance（IR）and inflammatory biomarker levels on type 2 diabetes mellitus（T2DM）among 1,903Inner Mongolians.
目的对1例血型血清学RhD为弱凝集的受试者进行分子生物学分析,明确其抗原减弱原因。方法选择2023年深圳市出关体检血型血清学检测为弱D的1例体检人员作为研究对象,采用序列特异性引物-聚合酶链式反应(SSP-PCR)对RhD,RhC,RhE基因型进行检...目的对1例血型血清学RhD为弱凝集的受试者进行分子生物学分析,明确其抗原减弱原因。方法选择2023年深圳市出关体检血型血清学检测为弱D的1例体检人员作为研究对象,采用序列特异性引物-聚合酶链式反应(SSP-PCR)对RhD,RhC,RhE基因型进行检测,使用Sanger测序法对RhD,RhC,RhE基因序列进行测序分析。结果该受试者与微柱凝集法抗-D为弱凝集,盐水试管法抗-D结果为阴性,不规则抗体筛查与直接抗人球蛋白试验结果均为阴性。Rhesus盒检测结果为上游RhD阳性,表明至少存在1段为部分D等位基因,或者下游RhD至少存在1段为部分D等位基因。基因测序结果提示该样本在第9外显子出现插入信号,根据NCBI genebank比对,该突变符合RhD*weak D type 2,GenBank:OM925755.1。结论该受试者血型血清学检测结果为弱D,主要原因可能为RhD外显子9第1碱基出现C碱基插入引发基因突变,致使外显子第一个氨基酸由甘氨酸翻译为丙氨酸,并引发后续基因错配导致氨基酸翻译错乱,从而使RhD血型抗原表达变弱。展开更多
In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel c...In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel classification approaches to this problem: one based on the use of the powerful type-2 fuzzy logic systems (type-2 FLS) and the other on the use of the discriminative sensitivity-based linear learning method (SBLLM). The use of prosodic features has been used in a plethora of practical applications, including speech-related applications, such as speaker and word recognition, emotion and accent identification, topic and sentence segmentation, and text-to-speech applications. In this paper, we continue to specifically focus on the Arabic language, as other languages have received a lot of attention in this regard. Moreover, we aim to improve the performance of our previously-used techniques, of which the support vector machine (SVM) method was the best performing, by applying the two above-mentioned powerful classification approaches. The recorded continuous speech is first segmented into sentences using both energy and time duration parameters. The prosodic features are then extracted from each sentence and fed into each of the two proposed classifiers so as to classify each sentence as a Question or a Non-Question sentence. Our extensive simulation work, based on a moderately-sized database, showed the two proposed classifiers outperform SVM in all of the experiments carried out, with the type-2 FLS classifier consistently exhibiting the best performance, because of its ability to handle all forms of uncertainties.展开更多
文摘The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ) to give dichlorobisaryltin(Ⅳ).The ~1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.
文摘A series of new Schiff base type macrocyclic crown ethers containing naphthalene ring were synthesized from 2,2'-di(o-formylnaphthoxy) ethyl ether or 1,2-di(o-formylnaphthoxy) ethane and four appropriate diamines. The chemical structures of the new compounds were characterized by elemental analysis, infrared spectra, nuclear magnetic resonance spectra and mass spectrometry.
文摘^(199)Hg NHR spectra of 18 Schiff base type arylmercury compounds have been studied.It was further confirmed that in the molecule of XC_6H_4CH=NC_6H_3-2-HgC1-4-CH_3 there exists an intramolecular N→Hg coordination via a four-membered ring.For the series of XC_6H_4CH=NC_6H_3-2-HgCl-4-CH_3(X is a para-or mera-substituent),there is a good linear correlation between δ^(199)Hg and Hammett's o constants.The influence of substituents of C-pheny1 ring on the δ ^(199)Hg can be explained in terms of the intramolecular N→Hg coordination.
文摘In the original publication,mistakenly first and corresponding affiliation is given as:Thermoelectricity Technology Center,Hangzhou Dahe Thermo-Magnetics Co.Ltd,Hangzhou 310053,ChinaThe correct first and corresponding affiliation is:State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China.
基金Project supported by the National Natural Science Foundation of China the Natural Science Foundation of Henan Province.
文摘Eight bis-,two tris-and two mono-crown ethers of Schiff base type have been pre- parcd by the reaction of 4'-formylbenzo-15-crown-5 with diamincs.Conductivity measurements show that the bis-crown ethers form 1:1 complexes(crown cther unit:metal ion)with sodium ion and 2:1 complexes with potassium,rubidium and ammonium ion,respectively.
基金funded by the Key Projects in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(No.2015BAD15B04)the National Natural Science Foundation of China(No.31600466)the Fundamental Research Funds for Jiangsu Key Laboratory of Biomass Energy and Material(No.JSBEM-S-201605)
文摘p-Menthane type monoterpene derivatives were identified as bio-based compounds with high herbicidal activities. In order to search novel p-menthane type monoterpene derivatives in good performance, a series of novel cis-p-menthane type Schiff base derivatives were designed and synthesized. All target products were easily available novel compounds and characterized by FT-IR,^1H NMR,^13 C NMR and ESI＋-MS. Their pre-emergence herbicidal activities against annual ryegrass were evaluated. The bioassays indicated that most of the target compounds displayed excellent herbicidal activities in pre-emergence treatment.
基金funded by the National Natural Science Foundation of China(grant No.41572117)Technological&Developmental Department of China Petroleum&Chemical Corporation(grants No.P13040 and P14128)China Geological Survey(grant No.DD20160175-1-1)
文摘Objective The Yubei area is located in the mid-east Maigaiti slope of southwestern Tarim Basin, China, with an exploration history of several years. Recent exploration has preliminarily indicated that the Ordovician carbonate formations in this area have some oil and gas potential. Carbonate microfacies provides material basis for reservoir development, seal formation and hydrocarbon generation. Therefore, this work utilized the standard microfacies （SMF） types to study the microfacies of the Ordovician formations in the Yubei area in order to provide theoretical basis for the next exploration.
文摘Polyesters consisting of substituted aromatic type Schiff base mesogenic unit andpolymethylene spacers were synthesized and their thermal transitions and liquid crystallineproperties were studied. The liquid crystalline behaviour has been characterized by differentialscanning calorimetry (DSC) and optical polarizing microscopy. Structural broadening bysubstitution of methoxy group in 2, 2' positions of the mesogenic core produce polymers withlower transition temperatures. Polymers synthesized from ortho and meta substituted phenylenediamine did not form a liquid crystal phase.
基金supported by the Beijing Scholars Program[BSP041]。
文摘The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.
文摘The influences of the ratio of the radius of atom A（rA） to radius of atom B（rB）, electronegativity and electron number were discussed on the Laves phase formation and the characteristics of Zr-based AB2 type hydrogen storage alloy. An enthalpy model of Zr-based AB2 alloy was obtained from known data and twelve Zr-based alloys were designed to test the model. The results show that the predicted values are in good agreement with the experimental values. The model can be used for predicting enthalpy values of Zr-based hydrogen storage alloys and settles a foundation for experiments.
文摘Magnetic field induced entropy change was investigated for La-Fe based NaZn13-type compounds with magnetic first-order phase transition. In view of magnetic refrigeration at room temperature, the developing of the materials and the understanding of the entropy change were., reviewed. For La-Fe-Si compounds, the entropy change about 29 J·kg^- 1·K^-1 was obtained at 190 K under the magnetic field of 5 T.While a large entropy change of about 15 J·kg^-1·K^-1 near room temperature under 5 T can be obtained by the substitution of Co for Fe in the compounds. It is found that the entropy change is mainly composed of that contributed from magnetic ordering and crystal lattice. The large entropy change consumed by lattice contribution is mainly due to the magnetic ordering one.
基金Project supported by the National Natural Science Foundation of China(Grant No.31670724)the National Key Research and Development Program of China(Grant Nos.2016YFC1305800 and 2016YFC1305805)the Startup Grant of Huazhong University of Science and Technology,China
文摘Knowledge-based scoring functions have been widely used for protein structure prediction, protein-small molecule, and protein-nucleic acid interactions, in which one critical step is to find an appropriate representation of protein structures. A key issue is to determine the minimal protein representations, which is important not only for developing of scoring func- tions but also for understanding the physics of protein folding. Despite significant progresses in simplifying residues into alphabets, few studies have been done to address the optimal number of atom types for proteins. Here, we have investigated the atom typing issue by classifying the 167 heavy atoms of proteins through 11 schemes with 1 to 20 atom types based on their physicochemical and functional environments. For each atom typing scheme, a statistical mechanics-based iterative method was used to extract atomic distance-dependent potentials from protein structures. The atomic distance-dependent pair potentials for different schemes were illustrated by several typical atom pairs with different physicochemical proper- ties. The derived potentials were also evaluated on a high-resolution test set of 148 diverse proteins for native structure recognition. It was found that there was a crossover around the scheme of four atom types in terms of the success rate as a function of the number of atom types, which means that four atom types may be used when investigating the basic folding mechanism of proteins. However, it was revealed by a close examination of typical potentials that 14 atom types were needed to describe the protein interactions at atomic level. The present study will be beneficial for the development of protein related scoring functions and the understanding of folding mechanisms.
文摘Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the corresponding products in high yields.
基金financially supported by the National Natural Science Foundation of China(Nos.91222201,21173165 and 20871098)the Program for New Century Excellent Talents in Universities from the Ministry of Education of China(No.NCET-10-0936)+4 种基金the State Key Laboratory of Structure Chemistry(20100014)the Provincial Natural Foundation(2011JQ2011) of Shaanxithe Education Committee Foundation of Shaanxi Province(11JK0588,12JK0577)Graduate Innovation and Creativity Fund(YZZ12038) of Northwest UniversityHong Kong Research Grants Council(HKBU 202407 and FRG/06-07/II-16)
文摘From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn（OAc）2.2H20 in the molar ratio of 1：1 or 1：2, the mononuclear [Zn（L）（H2O）] （1） or binuclear [Zn2（L）（OAc）2（H2O）] （2） are obtained, respectively. For both complexes 1 and 2, the unsaturated five-coordinate coordination environment to the catalytic active centers （Zn2＋ ions） permits the monomer insertion for the effective solution copolymerization of cyclohexene oxide and maleic anhydride. All the solution copolymerizations afford poly（ester-co-ether）s, while lower catalyst and co-catalyst concentrations are helpful for the formation of alternating polyester. Of the three co-catalysts, 4-（dimethylamino）pyridine is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers.
文摘The purpose of this study is to explore whether it is worthwhile to launch a routine diabetic retinopathy (DR) screening for blindness pre-vention among Chinese type 2 diabetes from different perspective based on the popula-tion-based study in Kinmen, Taiwan. A total of 971 community dwelling adults previously di-agnosed with type 2 diabetes in 1991-1993 un-derwent DR screening in 1999-2002 by a panel of ophthalmologists using on-site indirect oph-thalmoscopy and 45-degree color fundus retinal photographs. The cost-benefit analysis is used to evaluate the DR screening. In terms of bene-fit-cost ratio, the different screening programs for DR could save New Taiwan Dollars (NTD) from 14.38 to 36.83 in discounted costs for each dollar incurred in different screening years from the societal viewpoint for Taiwan and save NTD from 0.81 to 1.80 in different screening years from health care payer’s perspective. The av-erage estimate of willingness-to-pay to translate into benefit yields NTD from 937.8 to 4,689 be- nefits per case due to DR screening in different screening years during 10-year follow-up. The net present value of the DR screening were NTD from -167,318 to -307,251.2 in different screening years. In conclusion, it is worthwhile to initial a routine DR screening of Chinese type 2 diabetes for blindness prevention from the societal per-spective but not from consumer decision based on the willingness-to-pay perspective.
基金supported by the National Natural Science Foundation of China[Grant No.81773509][Grant No.81102190]
文摘This prospective study was designed to examine the combined influence of insulin resistance（IR）and inflammatory biomarker levels on type 2 diabetes mellitus（T2DM）among 1,903Inner Mongolians.
文摘目的对1例血型血清学RhD为弱凝集的受试者进行分子生物学分析,明确其抗原减弱原因。方法选择2023年深圳市出关体检血型血清学检测为弱D的1例体检人员作为研究对象,采用序列特异性引物-聚合酶链式反应(SSP-PCR)对RhD,RhC,RhE基因型进行检测,使用Sanger测序法对RhD,RhC,RhE基因序列进行测序分析。结果该受试者与微柱凝集法抗-D为弱凝集,盐水试管法抗-D结果为阴性,不规则抗体筛查与直接抗人球蛋白试验结果均为阴性。Rhesus盒检测结果为上游RhD阳性,表明至少存在1段为部分D等位基因,或者下游RhD至少存在1段为部分D等位基因。基因测序结果提示该样本在第9外显子出现插入信号,根据NCBI genebank比对,该突变符合RhD*weak D type 2,GenBank:OM925755.1。结论该受试者血型血清学检测结果为弱D,主要原因可能为RhD外显子9第1碱基出现C碱基插入引发基因突变,致使外显子第一个氨基酸由甘氨酸翻译为丙氨酸,并引发后续基因错配导致氨基酸翻译错乱,从而使RhD血型抗原表达变弱。
文摘In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel classification approaches to this problem: one based on the use of the powerful type-2 fuzzy logic systems (type-2 FLS) and the other on the use of the discriminative sensitivity-based linear learning method (SBLLM). The use of prosodic features has been used in a plethora of practical applications, including speech-related applications, such as speaker and word recognition, emotion and accent identification, topic and sentence segmentation, and text-to-speech applications. In this paper, we continue to specifically focus on the Arabic language, as other languages have received a lot of attention in this regard. Moreover, we aim to improve the performance of our previously-used techniques, of which the support vector machine (SVM) method was the best performing, by applying the two above-mentioned powerful classification approaches. The recorded continuous speech is first segmented into sentences using both energy and time duration parameters. The prosodic features are then extracted from each sentence and fed into each of the two proposed classifiers so as to classify each sentence as a Question or a Non-Question sentence. Our extensive simulation work, based on a moderately-sized database, showed the two proposed classifiers outperform SVM in all of the experiments carried out, with the type-2 FLS classifier consistently exhibiting the best performance, because of its ability to handle all forms of uncertainties.
