The pig-on-litter system is characterized by reduced environmental pollution and high-quality pork. It has won the support of the government and the acceptance of market. It is urgent to develop the supporting facilit...The pig-on-litter system is characterized by reduced environmental pollution and high-quality pork. It has won the support of the government and the acceptance of market. It is urgent to develop the supporting facilities and products to promote the comprehensive promotion of this technology. Based on the climatic and hydro- logical conditions in Jiangsu Province, we designed the removable deep-litter breed- ing shed. Its construction costs were lower than that of ordinary water-flushed pig- gery. In addition, this breeding system would not consolidate the land. The indoor ventilation and heat-conservation performances also met the requirements by pig-on- litter system. The removable shed can be promoted as an important supporting technology for the deep-litter breeding model in the eastern China.展开更多
A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wh...A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.展开更多
Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices (VBIED) and reduc...Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices (VBIED) and reduce the corresponding damage. Compared with a fixed bollard system, a removable bollard system provides more flexibility as it can be removed when needed. This paper first proposes a new type of K4-rated removable anti-ram bollard system. To simulate the collision of a vehicle hitting the bollard system, a finite element model was then built and verified through comparison of numerical simulation results and existing experimental results. Based on the orthogonal design method, the factors influencing the safety and economy of this proposed system were examined and sorted according to their importance. An optimal design scheme was then produced. Finally, to validate the effectiveness of the proposed design scheme, four dynamic impact tests, including two front impact tests and two side impact tests, have been conducted according to BSI Specifications. The residual rotation angles of the specimen are smaller than 30~ and satisfy the requirements of the BSI Specification.展开更多
In this paper we consider a nondivergent elliptic equation of second order whose leading coefficients are from some weight space. The sufficient condition of removability of a compact with respect to this equation in ...In this paper we consider a nondivergent elliptic equation of second order whose leading coefficients are from some weight space. The sufficient condition of removability of a compact with respect to this equation in the weight space of Holder functions was found.展开更多
Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study repo...Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study reports the effect of gender and location (maxilla vs. mandible) on the clinical performance of removable partial dentures (RPDs). Materials and Methods: A total of 100 Patients who had RPDs delivered between 1990-1995 were evaluated. A 4-point scoring system was used to assess seventeen criteria. These criteria include acceptance, stability, support, retention, adaptation, occlusion, integrity, and design of the pros-theses, rest and rest seat preparation, occlusal wear, esthetics, phonetics, tissue condition, mobility of abutments, gingival and plaque indices. The data were analyzed using Kruskal-Wallis and Mann-Whitney U non-parametric statistical tests. Results: The results showed that acceptance of RPDs was rated the lowest. Other reasons for failure were poor retention, lack of integrity of the prostheses and inadequate adaptation. Retention and design of major connectors attributed to Mandibular RPD failure. Success rate of 75% was observed in male compared with 67.2% for female. Maxillary RPDs showed a higher success rate (78%) compared with the mandibular (70.1%). No significant statistical difference in Alpha scores between female and male patients and between maxillary and mandibular RPDs (p < 0.05). Conclusions: The clinical performance of RPDs showed a higher success rate in male patients compared to female patients and the maxillary RPDs showed a higher success rate compared to mandibular.展开更多
The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients p...The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics Service in the Hospital Affiliated to Kinshasa University (Democratic Republic of Congo) were assessed for enrolment in this study. After applying exclusion criteria, 378 patients were included in the study, and randomly assigned into 2 groups. Oral health related quality of life (OHIP-23) and mastication time (MaT), number of chewing cycles (MaC), mastication frequency (MaF), and the sizes of the peanut fragments (FraS) were compared in both groups. Statistical significance was set at p < 0.05. Results: The average MaC, MaT, MaF, and FraS were 119 (± SD 53.70), 86.75 (±SD 35.35), 1.38 (±SD 0.25), and 3.3 (±SD 3.25) for the denture group and 77.9 (±SD 23.9), 60.2 (±SD 17.91), 1.29 (±SD 0.15), and 1.5 (±SD 0.7) for the non-denture group, respectively. Conclusion: The overall oral health related quality of life was best in the non-denture than denture.展开更多
Objective: The goal of the removable partial denture is to restore impaired esthetics and masticatory function by replacing missing teeth. The aim of this study was to establish a possible correla-tion between removab...Objective: The goal of the removable partial denture is to restore impaired esthetics and masticatory function by replacing missing teeth. The aim of this study was to establish a possible correla-tion between removable partial denture in acrylic resin use after 5 years and dental diseases. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics service of the Affiliated Hospital of Kinshasa University, Democratic Republic of Congo were assessed in this study. Patients were randomly assigned into 2 groups: Denture and non-denture group. Caries and periodontal diseases were compared between both groups. Statistical significance was set at p < 0.05. Results: The average age in the denture and non-denture-group was 53.15 (±SD 22.05) and 31.59 (±SD 11.98) years. Out of 160 teeth were decayed, both 110 teeth (68.75%) in the denture-group and 50 teeth (31.25%) in the non-denture group. The DMFT index calculated at start time of the study was 0.2 for both groups, after five years was 7.1 for the denture-group and 2.6 for the non-denture-group. The plaque index in the denture-group had an index of 1 and that of non-denture-group was 0.5. Conclusion: The relationship has been found between patients’ wearers a RPD and dental diseases.展开更多
Comprehensive Summary The strategy of removable glycosylation modification was used to overcome the low-efficiency problem encountered in the chemical synthesis of the mirror-image D-version of the immunoglobulin(Ig)-...Comprehensive Summary The strategy of removable glycosylation modification was used to overcome the low-efficiency problem encountered in the chemical synthesis of the mirror-image D-version of the immunoglobulin(Ig)-like domain of tropomyosin receptor kinase A(DlgCTrkA),a protein molecule needed for mirror-image screening of D-peptide ligands targeting this cell membrane receptor.It was found that O-linked-β-N-acetyl-D-glucosamine(O-GlcNAc)modification at^(D)Ser^(312),or^(D)Ser^(320)can significantly improve the efficiency of DlgCTrkA synthesis and folding,while O-GlcNAc modification at^(D)Ser^(330)showed barely any improvement.This study provides a new example demonstrating the power of the removable glycosylation modification strategy in the chemical synthesis and folding of difficult-to-obtain proteins.It also presents evidence that removable glycosylation modification at different sites would significantly affect the efficiency of protein folding promoted by this strategy.展开更多
Carvalho, Lucchesi and Murty proved that any 1-extendable graph G different from K2 and C2n has at least A(G) edge-disjoint removable ears, and any brick G distinct from K4 and C6 has at least A(G) - 2 removable e...Carvalho, Lucchesi and Murty proved that any 1-extendable graph G different from K2 and C2n has at least A(G) edge-disjoint removable ears, and any brick G distinct from K4 and C6 has at least A(G) - 2 removable edges, where A(G) denotes the maximum degree of G. In this paper, we improve the lower bounds for numbers of removable ears and removable edges of 1-extendable graphs. It is proved that any 1-extendable graph G different from K2 and C2n has at least x′(G) edge-disjoint removable ears, and any brick G distinct from Ka and Ce has at least x′(G) - 2 removable edges, where x′(G) denotes the edge-chromatic number of G. Key words 1-extendable graphs, removable ear, removable edge.展开更多
Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermal...Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers (HP-NCNFs) through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m2-g 1, which is 2.6 times higher than that (323.2 m2.g 1) of conventional N-doped carbon nanofibers (NCNFs). Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction (ORR) in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commerdal Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional (3D) cross-linked structures, graphene-like structure on the edge of the HP- NCNFs, high specific surface area, and a hierarchically porous structure.展开更多
A Caccioppoli type estimate is established for a class of second order PDEs of divergence type, and its removable singularities of Hausdorff dimension greater than zero is obtained.
This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external com...This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external computers on the propagation of computer virus. The stability results of equilibrium point are derived by Hurwitz criterion and Bendixson Dulac criterion. The effectiveness of the proposed results is shown by numerical simulation. In order to show the superiority of the proposed model,some comparisons with the existing models are presented. The acceptable threshold and the reasonable strategies for suppressing the propagation of computer virus are also suggested,respectively.展开更多
Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated wi...Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated with sodium halides(NaBr and NaI)are presented to capture elemental mercury(Hg^(0))from flue gas.The modified RM underwent comprehensive characterization,including analysis of its textural qualities,crystal structure,chemical composition,and thermal properties.The results indicate that the halide impregnation substantially impacts the surface area and pore size of the RM.Hg^(0) removal performance was evaluated on a fixed-bed reactor in simulated flue gas(consisting of N_(2),O_(2),CO_(2),NO and SO_(2),etc.)on a modified RM.At an optimal adsorption temperature of 160℃,NaI-modified sorbent(RMI5)offers a removal efficiency of 98%in a mixture of gas,including O_(2),NO and HCl.Furthermore,pseudo-second-order model fitting results demonstrate the chemisorption mechanism for the adsorption of Hg^(0) in kinetic investigations.展开更多
The Fenton-like reaction between Cu^(2+)and H_(2)O_(2)was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten.The microstructure evolution and material removal rate o...The Fenton-like reaction between Cu^(2+)and H_(2)O_(2)was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten.The microstructure evolution and material removal rate of tungsten during polishing process were investigated via scanning electron microscopy,X-ray photoelectron spectroscopy,ultraviolet−visible spectrophotometry,and electrochemical experiments.The passivation behavior and material removal mechanism were discussed.Results show that the use of mixed H_(2)O_(2)+Cu(NO_(3))_(2)oxidant can achieve higher polishing efficiency and surface quality compared with the single oxidant Cu(NO_(3))_(2)or H_(2)O_(2).The increase in material removal rate is attributed to the rapid oxidation of W into WO_(3)via the chemical reaction between the substrate and hydroxyl radicals produced by the Fenton-like reaction.In addition,material removal rate and static etch rate exhibit significantly different dependencies on the concentration of Cu(NO_(3))_(2),while the superior oxidant for achieving the balance between polishing efficiency and surface quality is 0.5 wt.%H_(2)O_(2)+1.0 wt.%Cu(NO_(3))_(2).展开更多
In this paper,some results on remorable sets of entire and meromorphic functions in the sense of Borel Theorem are obtained. Among them we prove that there exists a seque nce of discs(D_n)with radii tending to the inf...In this paper,some results on remorable sets of entire and meromorphic functions in the sense of Borel Theorem are obtained. Among them we prove that there exists a seque nce of discs(D_n)with radii tending to the infinity such that,for any entire function f(z) with a positive and finite order,Borel Theorem always holds in.展开更多
An edge e of a k-connected graph G is said to be a removable edge if G e is still kconnected, where G e denotes the graph obtained from G by deleting e to get G - e, and for any end vertex of e with degree k - 1 in ...An edge e of a k-connected graph G is said to be a removable edge if G e is still kconnected, where G e denotes the graph obtained from G by deleting e to get G - e, and for any end vertex of e with degree k - 1 in G - e, say x, delete x, and then add edges between any pair of non-adjacent vertices in NG-e(x). The existence of removable edges of k-connected graphs and some properties of 3-connected graphs and 4-connected graphs have been investigated. In the present paper, we investigate some properties of k-connected graphs and study the distribution of removable edges on a cycle in a k-connected graph (k ≥ 4).展开更多
An edge e of a k-connected graph G is said to be a removable edge if G O e is still k-connected, where G O e denotes the graph obtained from G by the following way: deleting e to get G - e, and for any end vertex of ...An edge e of a k-connected graph G is said to be a removable edge if G O e is still k-connected, where G O e denotes the graph obtained from G by the following way: deleting e to get G - e, and for any end vertex of e with degree k - 1 in G - e, say x, deleting x, and then adding edges between any pair of non-adjacent vertices in NG-e (x). The existence of removable edges of k-connected graphs and some properties of k-connected graphs have been investigated. In the present paper, we investigate the distribution of removable edges on a spanning tree of a k-connected graph (k ≥ 4).展开更多
Synthesis and photochemistry of acridin-9-ylmethoxycarbonyl (Amoc) as a new photochemically removable protecting group for alcohols were described. Three carbonates of alcohols 1-3 were synthesized through condensat...Synthesis and photochemistry of acridin-9-ylmethoxycarbonyl (Amoc) as a new photochemically removable protecting group for alcohols were described. Three carbonates of alcohols 1-3 were synthesized through condensation of 9-hydroxymethylacridine and chloroformates of alcohols, including benzyl alcohol, phenethyl alcohol and one galactose derivative. The photolysis of protected alcohols can efficiently release the corresponding alcohol in the efficiencies (Qulε) of 100-200 (quantum yield Qul=0.011-0.023, and molar absorptivity ε= 9.1 × 10^3-9.8 × 10^3 mol^-1·L·cm^-1) under 360 nm light.展开更多
BACKGROUND Gastric bezoars are indigestible masses that can lead to gastrointestinal ob-struction and ulceration.Standard treatments include endoscopic mechanical lithotripsy with a polypectomy snare and Coca-Cola dis...BACKGROUND Gastric bezoars are indigestible masses that can lead to gastrointestinal ob-struction and ulceration.Standard treatments include endoscopic mechanical lithotripsy with a polypectomy snare and Coca-Cola dissolution therapy or a combination of both approaches.However,giant bezoars frequently require multiple treatment sessions and extended hospital stays.Additionally,snare-based mechanical fragmentation may be limited by factors such as bezoar size,shape,density,slipperiness,and restricted working space.In cases where refra-ctory giant bezoars are unresponsive to traditional methods,surgical intervention is often necessary.CASE SUMMARY A 57-year-old male with a history of type 2 diabetes presented with severe epigastric pain and vomiting.Endoscopy revealed two large phytobezoars and a gastric ulcer.Initial attempts at mechanical fragmentation with a polypectomy snare and Coca-Cola ingestion for dissolution were unsuccessful due to the large size and complex structure of the bezoars.An innovative approach using snare-tip electrocautery was then employed.It successfully penetrated the slippery,hard surface of the bezoars and fragmented them into smaller pieces.The patient was subsequently treated with Coca-Cola ingestion,enzyme supplements,and proton pump inhibitors.He was discharged without complications following the endoscopic sessions.CONCLUSION Snare-tip electrocautery is a safe,cost-effective,and minimally invasive alter-native for managing large,refractory gastric bezoars.This is a valuable option in resource-limited settings.展开更多
Perfluoroalkyl acid analogs(PFAAs)are a class of chemically stable environmentally persistent organic pollutants(POPs)that are difficult to degrade and have a strong capacity to accumulate in the human body.PFAAs have...Perfluoroalkyl acid analogs(PFAAs)are a class of chemically stable environmentally persistent organic pollutants(POPs)that are difficult to degrade and have a strong capacity to accumulate in the human body.PFAAs have been found to be biotoxic to humans and have been detected in various environmental media,especially in the cryosphere at trace concentrations.The cryosphere,sensitively responds to climate change,plays a crucial role in the global water,carbon and energy cycles.However,researches on cryosphere PFAAs especially in Tibetan Plateau(TP)is limited.Therefore,we summarize the physicochemical properties,physiological toxicity,spatiotemporal distribution,sources,diffusion and migration pathways,as well as analysis and removal methods of PFAAs in the cryosphere regions.The results show that PFAAs pollutants are mainly produced and distributed in the more economically developed countries in Europe and the United States,as well as in East Asia,and PFAAs can be transported by atmospheric circulation and water cycle to remote regions including cryosphere regions.The current detection methods for PFAAs in cryosphere need to be further refined for increased accuracy and convenience.There is also a need to develop more effective removal methods that will reduce the environmental and human threats posed by these PFAAs.Finally,we propose key scientific questions for future research in cryosphere including PFAAs redistribution influenced by cryosphere changes,human activities,and the interaction of other spheres.展开更多
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund(CX(12)5013)~~
文摘The pig-on-litter system is characterized by reduced environmental pollution and high-quality pork. It has won the support of the government and the acceptance of market. It is urgent to develop the supporting facilities and products to promote the comprehensive promotion of this technology. Based on the climatic and hydro- logical conditions in Jiangsu Province, we designed the removable deep-litter breed- ing shed. Its construction costs were lower than that of ordinary water-flushed pig- gery. In addition, this breeding system would not consolidate the land. The indoor ventilation and heat-conservation performances also met the requirements by pig-on- litter system. The removable shed can be promoted as an important supporting technology for the deep-litter breeding model in the eastern China.
文摘A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.
文摘Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices (VBIED) and reduce the corresponding damage. Compared with a fixed bollard system, a removable bollard system provides more flexibility as it can be removed when needed. This paper first proposes a new type of K4-rated removable anti-ram bollard system. To simulate the collision of a vehicle hitting the bollard system, a finite element model was then built and verified through comparison of numerical simulation results and existing experimental results. Based on the orthogonal design method, the factors influencing the safety and economy of this proposed system were examined and sorted according to their importance. An optimal design scheme was then produced. Finally, to validate the effectiveness of the proposed design scheme, four dynamic impact tests, including two front impact tests and two side impact tests, have been conducted according to BSI Specifications. The residual rotation angles of the specimen are smaller than 30~ and satisfy the requirements of the BSI Specification.
文摘In this paper we consider a nondivergent elliptic equation of second order whose leading coefficients are from some weight space. The sufficient condition of removability of a compact with respect to this equation in the weight space of Holder functions was found.
文摘Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study reports the effect of gender and location (maxilla vs. mandible) on the clinical performance of removable partial dentures (RPDs). Materials and Methods: A total of 100 Patients who had RPDs delivered between 1990-1995 were evaluated. A 4-point scoring system was used to assess seventeen criteria. These criteria include acceptance, stability, support, retention, adaptation, occlusion, integrity, and design of the pros-theses, rest and rest seat preparation, occlusal wear, esthetics, phonetics, tissue condition, mobility of abutments, gingival and plaque indices. The data were analyzed using Kruskal-Wallis and Mann-Whitney U non-parametric statistical tests. Results: The results showed that acceptance of RPDs was rated the lowest. Other reasons for failure were poor retention, lack of integrity of the prostheses and inadequate adaptation. Retention and design of major connectors attributed to Mandibular RPD failure. Success rate of 75% was observed in male compared with 67.2% for female. Maxillary RPDs showed a higher success rate (78%) compared with the mandibular (70.1%). No significant statistical difference in Alpha scores between female and male patients and between maxillary and mandibular RPDs (p < 0.05). Conclusions: The clinical performance of RPDs showed a higher success rate in male patients compared to female patients and the maxillary RPDs showed a higher success rate compared to mandibular.
文摘The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics Service in the Hospital Affiliated to Kinshasa University (Democratic Republic of Congo) were assessed for enrolment in this study. After applying exclusion criteria, 378 patients were included in the study, and randomly assigned into 2 groups. Oral health related quality of life (OHIP-23) and mastication time (MaT), number of chewing cycles (MaC), mastication frequency (MaF), and the sizes of the peanut fragments (FraS) were compared in both groups. Statistical significance was set at p < 0.05. Results: The average MaC, MaT, MaF, and FraS were 119 (± SD 53.70), 86.75 (±SD 35.35), 1.38 (±SD 0.25), and 3.3 (±SD 3.25) for the denture group and 77.9 (±SD 23.9), 60.2 (±SD 17.91), 1.29 (±SD 0.15), and 1.5 (±SD 0.7) for the non-denture group, respectively. Conclusion: The overall oral health related quality of life was best in the non-denture than denture.
文摘Objective: The goal of the removable partial denture is to restore impaired esthetics and masticatory function by replacing missing teeth. The aim of this study was to establish a possible correla-tion between removable partial denture in acrylic resin use after 5 years and dental diseases. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics service of the Affiliated Hospital of Kinshasa University, Democratic Republic of Congo were assessed in this study. Patients were randomly assigned into 2 groups: Denture and non-denture group. Caries and periodontal diseases were compared between both groups. Statistical significance was set at p < 0.05. Results: The average age in the denture and non-denture-group was 53.15 (±SD 22.05) and 31.59 (±SD 11.98) years. Out of 160 teeth were decayed, both 110 teeth (68.75%) in the denture-group and 50 teeth (31.25%) in the non-denture group. The DMFT index calculated at start time of the study was 0.2 for both groups, after five years was 7.1 for the denture-group and 2.6 for the non-denture-group. The plaque index in the denture-group had an index of 1 and that of non-denture-group was 0.5. Conclusion: The relationship has been found between patients’ wearers a RPD and dental diseases.
基金supported by the National Natural Science Foundation of China(Nos.22227810,22277020,22307061)China Postdoctoral Science Foundation(No.2022M721801)the Beijing Life Science Academy(No.2023000cc0130).
文摘Comprehensive Summary The strategy of removable glycosylation modification was used to overcome the low-efficiency problem encountered in the chemical synthesis of the mirror-image D-version of the immunoglobulin(Ig)-like domain of tropomyosin receptor kinase A(DlgCTrkA),a protein molecule needed for mirror-image screening of D-peptide ligands targeting this cell membrane receptor.It was found that O-linked-β-N-acetyl-D-glucosamine(O-GlcNAc)modification at^(D)Ser^(312),or^(D)Ser^(320)can significantly improve the efficiency of DlgCTrkA synthesis and folding,while O-GlcNAc modification at^(D)Ser^(330)showed barely any improvement.This study provides a new example demonstrating the power of the removable glycosylation modification strategy in the chemical synthesis and folding of difficult-to-obtain proteins.It also presents evidence that removable glycosylation modification at different sites would significantly affect the efficiency of protein folding promoted by this strategy.
基金supported by the National Science Foundation of China under Grant No.10831001the Fujian Provincial Department of Education under Grant No.JA08223
文摘Carvalho, Lucchesi and Murty proved that any 1-extendable graph G different from K2 and C2n has at least A(G) edge-disjoint removable ears, and any brick G distinct from K4 and C6 has at least A(G) - 2 removable edges, where A(G) denotes the maximum degree of G. In this paper, we improve the lower bounds for numbers of removable ears and removable edges of 1-extendable graphs. It is proved that any 1-extendable graph G different from K2 and C2n has at least x′(G) edge-disjoint removable ears, and any brick G distinct from Ka and Ce has at least x′(G) - 2 removable edges, where x′(G) denotes the edge-chromatic number of G. Key words 1-extendable graphs, removable ear, removable edge.
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 21471016 and 21271023) and the 111 Project (No. B07012).
文摘Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers (HP-NCNFs) through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m2-g 1, which is 2.6 times higher than that (323.2 m2.g 1) of conventional N-doped carbon nanofibers (NCNFs). Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction (ORR) in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commerdal Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional (3D) cross-linked structures, graphene-like structure on the edge of the HP- NCNFs, high specific surface area, and a hierarchically porous structure.
基金Supported by National Natural Science Foundation (No.49805005)partially by Research Foundation of Northern Jiaotong University (2002SM061)
文摘A Caccioppoli type estimate is established for a class of second order PDEs of divergence type, and its removable singularities of Hausdorff dimension greater than zero is obtained.
基金supported by the National Natural Science Foundation of China ( 61503052, 61503050, 61603065, 61573075)Scientific and Technological Research Program of Chongqing Municipal Education Commission ( KJQN201801120, KJQN201801104,KJ17092060 )+1 种基金China Postdoctoral Science Foundation ( 2017M612911 )Chongqing Science and Technology Commission Technology Innovation and Application Demonstration Project ( cstc2018jscx-msybX0049)
文摘This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external computers on the propagation of computer virus. The stability results of equilibrium point are derived by Hurwitz criterion and Bendixson Dulac criterion. The effectiveness of the proposed results is shown by numerical simulation. In order to show the superiority of the proposed model,some comparisons with the existing models are presented. The acceptable threshold and the reasonable strategies for suppressing the propagation of computer virus are also suggested,respectively.
基金supported by the National Natural Science Foundation of China(22278066,21776039)the National Key R&D Program of China(2023YFB4103001)The Fundamental Research Funds for the Central Universities(DUT2021TB03).
文摘Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated with sodium halides(NaBr and NaI)are presented to capture elemental mercury(Hg^(0))from flue gas.The modified RM underwent comprehensive characterization,including analysis of its textural qualities,crystal structure,chemical composition,and thermal properties.The results indicate that the halide impregnation substantially impacts the surface area and pore size of the RM.Hg^(0) removal performance was evaluated on a fixed-bed reactor in simulated flue gas(consisting of N_(2),O_(2),CO_(2),NO and SO_(2),etc.)on a modified RM.At an optimal adsorption temperature of 160℃,NaI-modified sorbent(RMI5)offers a removal efficiency of 98%in a mixture of gas,including O_(2),NO and HCl.Furthermore,pseudo-second-order model fitting results demonstrate the chemisorption mechanism for the adsorption of Hg^(0) in kinetic investigations.
文摘The Fenton-like reaction between Cu^(2+)and H_(2)O_(2)was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten.The microstructure evolution and material removal rate of tungsten during polishing process were investigated via scanning electron microscopy,X-ray photoelectron spectroscopy,ultraviolet−visible spectrophotometry,and electrochemical experiments.The passivation behavior and material removal mechanism were discussed.Results show that the use of mixed H_(2)O_(2)+Cu(NO_(3))_(2)oxidant can achieve higher polishing efficiency and surface quality compared with the single oxidant Cu(NO_(3))_(2)or H_(2)O_(2).The increase in material removal rate is attributed to the rapid oxidation of W into WO_(3)via the chemical reaction between the substrate and hydroxyl radicals produced by the Fenton-like reaction.In addition,material removal rate and static etch rate exhibit significantly different dependencies on the concentration of Cu(NO_(3))_(2),while the superior oxidant for achieving the balance between polishing efficiency and surface quality is 0.5 wt.%H_(2)O_(2)+1.0 wt.%Cu(NO_(3))_(2).
基金Project partially supported by the National Natural Science Foundation of China
文摘In this paper,some results on remorable sets of entire and meromorphic functions in the sense of Borel Theorem are obtained. Among them we prove that there exists a seque nce of discs(D_n)with radii tending to the infinity such that,for any entire function f(z) with a positive and finite order,Borel Theorem always holds in.
基金Supported by the Science-technology Foundation for Young Scientists of Fujian Province (Grant No. 2007F3070) and National Natural Science Foundation of China (Grant No. 10831001)
文摘An edge e of a k-connected graph G is said to be a removable edge if G e is still kconnected, where G e denotes the graph obtained from G by deleting e to get G - e, and for any end vertex of e with degree k - 1 in G - e, say x, delete x, and then add edges between any pair of non-adjacent vertices in NG-e(x). The existence of removable edges of k-connected graphs and some properties of 3-connected graphs and 4-connected graphs have been investigated. In the present paper, we investigate some properties of k-connected graphs and study the distribution of removable edges on a cycle in a k-connected graph (k ≥ 4).
基金Supported by the National Natural Science Foundation of China(No.11171134)the Fujian Province Science Foundation(No.2013J01014,2011J01015,2007F3070)
文摘An edge e of a k-connected graph G is said to be a removable edge if G O e is still k-connected, where G O e denotes the graph obtained from G by the following way: deleting e to get G - e, and for any end vertex of e with degree k - 1 in G - e, say x, deleting x, and then adding edges between any pair of non-adjacent vertices in NG-e (x). The existence of removable edges of k-connected graphs and some properties of k-connected graphs have been investigated. In the present paper, we investigate the distribution of removable edges on a spanning tree of a k-connected graph (k ≥ 4).
基金Project supported by the National Natural Science Foundation of China (No. 30470444).
文摘Synthesis and photochemistry of acridin-9-ylmethoxycarbonyl (Amoc) as a new photochemically removable protecting group for alcohols were described. Three carbonates of alcohols 1-3 were synthesized through condensation of 9-hydroxymethylacridine and chloroformates of alcohols, including benzyl alcohol, phenethyl alcohol and one galactose derivative. The photolysis of protected alcohols can efficiently release the corresponding alcohol in the efficiencies (Qulε) of 100-200 (quantum yield Qul=0.011-0.023, and molar absorptivity ε= 9.1 × 10^3-9.8 × 10^3 mol^-1·L·cm^-1) under 360 nm light.
文摘BACKGROUND Gastric bezoars are indigestible masses that can lead to gastrointestinal ob-struction and ulceration.Standard treatments include endoscopic mechanical lithotripsy with a polypectomy snare and Coca-Cola dissolution therapy or a combination of both approaches.However,giant bezoars frequently require multiple treatment sessions and extended hospital stays.Additionally,snare-based mechanical fragmentation may be limited by factors such as bezoar size,shape,density,slipperiness,and restricted working space.In cases where refra-ctory giant bezoars are unresponsive to traditional methods,surgical intervention is often necessary.CASE SUMMARY A 57-year-old male with a history of type 2 diabetes presented with severe epigastric pain and vomiting.Endoscopy revealed two large phytobezoars and a gastric ulcer.Initial attempts at mechanical fragmentation with a polypectomy snare and Coca-Cola ingestion for dissolution were unsuccessful due to the large size and complex structure of the bezoars.An innovative approach using snare-tip electrocautery was then employed.It successfully penetrated the slippery,hard surface of the bezoars and fragmented them into smaller pieces.The patient was subsequently treated with Coca-Cola ingestion,enzyme supplements,and proton pump inhibitors.He was discharged without complications following the endoscopic sessions.CONCLUSION Snare-tip electrocautery is a safe,cost-effective,and minimally invasive alter-native for managing large,refractory gastric bezoars.This is a valuable option in resource-limited settings.
基金supported by the Gansu Provincial Science and Technology Program(22ZD6FA005)West Light Foundation of The Chinese Academy of Sciences(xbzg-zdsys-202306)+2 种基金Science Fund for Creative Research Groups of Gansu Province(Grant No.23JRRA567)Taishan Scholars Program of Shandong Province(No.tsqn202312158)Key Research and Development Program of Gansu Province(22YF7FA041)。
文摘Perfluoroalkyl acid analogs(PFAAs)are a class of chemically stable environmentally persistent organic pollutants(POPs)that are difficult to degrade and have a strong capacity to accumulate in the human body.PFAAs have been found to be biotoxic to humans and have been detected in various environmental media,especially in the cryosphere at trace concentrations.The cryosphere,sensitively responds to climate change,plays a crucial role in the global water,carbon and energy cycles.However,researches on cryosphere PFAAs especially in Tibetan Plateau(TP)is limited.Therefore,we summarize the physicochemical properties,physiological toxicity,spatiotemporal distribution,sources,diffusion and migration pathways,as well as analysis and removal methods of PFAAs in the cryosphere regions.The results show that PFAAs pollutants are mainly produced and distributed in the more economically developed countries in Europe and the United States,as well as in East Asia,and PFAAs can be transported by atmospheric circulation and water cycle to remote regions including cryosphere regions.The current detection methods for PFAAs in cryosphere need to be further refined for increased accuracy and convenience.There is also a need to develop more effective removal methods that will reduce the environmental and human threats posed by these PFAAs.Finally,we propose key scientific questions for future research in cryosphere including PFAAs redistribution influenced by cryosphere changes,human activities,and the interaction of other spheres.