Agricultural cooperative economic organization for water-saving irrigation in arid areas is a new form of economic organization in production,operation and management during the application process of water-saving irr...Agricultural cooperative economic organization for water-saving irrigation in arid areas is a new form of economic organization in production,operation and management during the application process of water-saving irrigation technologies.Currently,there are few researches on this cooperative economic organization.In this study,connotations of cooperative economic organizations for water-saving irrigation are specifically defined,and the characteristics and functions of this cooperative economic organization are analyzed.Based on that,several suggestions are proposed on the continuous development of cooperative economic organizations for water-saving irrigation.展开更多
To achieve an on-demand and dynamic composition model of inter-organizational business processes, a new approach for business process modeling and verification is introduced by using the pi-calculus theory. A new busi...To achieve an on-demand and dynamic composition model of inter-organizational business processes, a new approach for business process modeling and verification is introduced by using the pi-calculus theory. A new business process model which is multi-role, multi-dimensional, integrated and dynamic is proposed relying on inter-organizational collaboration. Compatible with the traditional linear sequence model, the new model is an M x N multi-dimensional mesh, and provides horizontal and vertical formal descriptions for the collaboration business process model. Finally, the pi-calculus theory is utilized to verify the deadlocks, livelocks and synchronization of the example models. The result shows that the proposed approach is efficient and applicable in inter-organizational business process modeling.展开更多
The current rural community self-organizing of China is closely related with the rural social stability as well as economic and social development. However, the current rural community self-organizing construction fal...The current rural community self-organizing of China is closely related with the rural social stability as well as economic and social development. However, the current rural community self-organizing construction falls far behind the requirements of realistic practice all over China, which greatly affects the advancement of the rural modernization of China. On the other hand, social work provides a unique perspective and method to deal with these problems. Its service philosophy of selfservice as well as its humanitarian value and practical working methods provide reality conformity for the intervention into rural community self-organizing, making it conductive to improving the social relations between rural community residents and possible to realize the mutual development of rural community and rural community residents.展开更多
The mechanical properties of Ti-23Al-17Nb (mole fraction,%) laser beam welding alloy joint at room temperature are comparable to that of the base materials.However,the strength and ductility of the as-welded joint det...The mechanical properties of Ti-23Al-17Nb (mole fraction,%) laser beam welding alloy joint at room temperature are comparable to that of the base materials.However,the strength and ductility of the as-welded joint deteriorate seriously after high temperature circulation.The effect of post-welded heat treatment on the microstructure and mechanical properties of the joint was investigated.The heat treatment was taken at 980 ℃ for 1.5 h,then furnace cooling and air cooling were performed separately.The results indicate that proper post-welded heat treatment improves the ductility of the joint at high temperature.展开更多
The effects of minor Sr, Sn and Sc addition on the as-cast microstructure and mechanical properties of the ZA84 magnesium alloy were compared. The results indicate that addition of 0.1%Sr, 0.5%Sn or 0.3%Sc (mass fract...The effects of minor Sr, Sn and Sc addition on the as-cast microstructure and mechanical properties of the ZA84 magnesium alloy were compared. The results indicate that addition of 0.1%Sr, 0.5%Sn or 0.3%Sc (mass fraction) to the ZA84 alloy can refine the grains of the alloy. Furthermore, addition of 0.1%Sr to the ZA84 alloy does not obviously change the morphology and distribution of Mg32(Al,Zn)49 phase. However, addition of 0.5%Sn or 0.3%Sc not only refines and modifies the Mg32(Al,Zn)49 phase but also suppresses the formation of Mg32(Al,Zn)49 phase, especially with the addition of 0.3%Sc. Furthermore, addition of 0.1%Sr, 0.5%Sn or 0.3%Sc to the ZA84 alloy improves the tensile properties at room temperature and 150℃, especially with the addition of 0.1%Sr and 0.3%Sc. However, addition of 0.1%Sr is not beneficial to the creep properties, and addition of 0.5%Sn has no obvious influence on the creep properties. Oppositely, addition of 0.3%Sc to the ZA84 alloy greatly improves the creep properties.展开更多
The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing...The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing milieu present in human tissues, and that stimulate tissue repair and regeneration. To be clinically effective, these environments must replicate, as closely as possible, the main characteristics of the native extracellular matrix(ECM) on a cellular and subcellular scale. Photo-fabrication techniques have already been used to generate 3D environments with precise architectures and heterogeneous composition, through a multi-layer procedure involving the selective photocrosslinking reaction of a light-sensitive prepolymer. Cells and therapeutic molecules can be included in the initial hydrogel precursor solution, and processed into 3D constructs. Recently, photofabrication has also been explored to dynamically modulate hydrogel features in real time, providing enhanced control of cell fate and delivery of bioactive compounds. This paper focuses on the use of 3D photo-fabrication techniques to produce advanced constructs for tissue regeneration and drug delivery applications. State-of-the-art photo-fabrication techniques are described, with emphasis on the operating principles and biofabrication strategies to create spatially controlled patterns of cells and bioactive factors. Considering its fast processing, spatiotemporal control, high resolution, and accuracy, photo-fabrication is assuming a critical role in the design of sophisticated 3D constructs. This technology is capable of providing appropriate environments for tissue regeneration, and regulating the spatiotemporal delivery of therapeutics.展开更多
This study addresses current status of ESSQ management and integration in steel production organisation. The idea is to benchmark maturity levels with the leading Finnish international companies. The examination has b...This study addresses current status of ESSQ management and integration in steel production organisation. The idea is to benchmark maturity levels with the leading Finnish international companies. The examination has been done in compliance with applied maturity model developed by the target corporation. When examining the benchmarked companies through the ESSQ framework, we found that a similar framework cannot be found in any other company as such; instead, operations are distributed under different organisations. Although many sources criticise system-based development, the results of this study indicate that it is nevertheless an efficient way to develop operations.展开更多
Oyster extract is an effective bioactivity component. It has abundant nutritional value and antiviral, antitumor and im- mune defense fimctions. The role of oyster extract in treating liver injury has been paid more a...Oyster extract is an effective bioactivity component. It has abundant nutritional value and antiviral, antitumor and im- mune defense fimctions. The role of oyster extract in treating liver injury has been paid more attention. We use Wistar rats to make alcoholic liver disease model through injecting alcohol into rats' stomachs. These rats were randomly divided into five groups: model group, control group, low-dose, middle-dose and high-dose experimental group with a dose of 0.12gkg-1, 0.40gkg-1, and 1.20gkg-1 alcoholic. After nine weeks, serum biomarkers (ALT, AST, TG and TCHO), malondialdehyde (MDA), glutathione (GSH), C3a, CSa, IL-17, TNF-a, anti-MAA-HAS IgC~ CD3+, CD4+, CDS+, NK cell activation and zinc content were assessed. The results showed that the serum biomarkers(ALT, AST, TG and TCHO), MDA content, anti-MAA-HSA IgG, serum C3a, CSa IL-17 and TNF-a levels of oyster extract treatment groups were significantly decreased in comparison with model group. On the contrary, GSH showed ad- verse trend. Serum CD3+, CD4+ and NK cell activation were significantly increased in middle-dose group and high-dose group compared with model group, and there was decrease of CD8+ activity in high-dose group. Plasma Zn level was decreased in model group compared with that in control group. Meanwhile, Mean plasma Zn levels increased dramatically following the dose increase of a given oyster extract.展开更多
AIM: To evaluate immunological protection of nitric ox- ide (NO) in hepatopulmonary syndrome and probable mechanisms of ischemia-reperfusion (IR) injury in rat liver transplantation, METHODS: Sixty-six healthy m...AIM: To evaluate immunological protection of nitric ox- ide (NO) in hepatopulmonary syndrome and probable mechanisms of ischemia-reperfusion (IR) injury in rat liver transplantation, METHODS: Sixty-six healthy male Wistar rats were randomly divided into three groups (11 donor/recipi-ent pairs). In group 11, organ preservation solution was lactated Ringer's solution with heparin 10 000/μL at 4℃. In groups I and 111, the pLeservation solution added, respectively, L-arginine or Ng-L-arginine methyl ester (L-NAME) (1 mmol/L) based on group 11, and recipients were injected with L-arginine or L-NAME (50 mg/kg) in the anhepatic phase. Grafted livers in each group were stored for 6 h and implanted into recipi- ents. Five rats were used for observation of postopera- tive survival in each group. The other six rats in each group were used to obtain tissue samples, and execut- ed at 3 h and 24 h after transplantation. The levels of alanine aminotransferase (ALT), tumor necrosis factor (TNF)-a and NO metabolites (NOx) were detected, and expression of NO synthase, TNF-α and intercellular adhesion molecule 1 (ICAM-1) was examined by tri- phosphopyridine nucleotide diaphorase histochemical and immunohistochemical staining. RESULTS: By supplementing L-arginine to strengthen the NO pathway, a high survival rate was achieved and hepatic function was improved. One-week sur- viral rate of grafted liver recipients in group I was significantly increased (28.8 4±36.6 d ys 4 4±1.7 d, P 〈 0.01) as compared with groups 11 and Ill. Serum levels of ALT in group ] were 2-7 times less than those in groups 11 and 11I (P 〈 0.01). The cyclic guanosine monophosphate (cGMP) levels in liver tissue and NOx in group I were 3-4 times higher than those of group 11 after 3 h and 24 h reperfusion, while in group ]]], they were significantly reduced as compared with those in group ]1 (P 〈 0.01). The levels of TNF-(z in group I were significantly lower than in group Ⅱ after 3 h and 24 h reperfusion (P 〈 0.01), while being sig- nificantly higher in group Ⅲ than group Ⅱ (P 〈 0.01). Histopathology revealed more severe tissue damage in graft liver and lung tissues, and a more severe in- flammatory response of the recipient after using NO synthase inhibitor, while the pathological damage to grafted liver and the recipient's lung tissues was signifi-cantly reduced in group I after 3 h and 24 h reperfu- sion. A small amount of constitutive NO synthase (cNOS) was expressed in liver endothelial cells after 6 h cold storage, but there was no expression of inducible NO synthase (iNOS). Expression of cNOS was particularly significant in vascular endothelial cells and liver cells at 3 h and 24 h after reperfusion in group Ⅱ but expres- sion of iNOS and ICAM-1 was low in group I. There was diffuse strong expression of ICAM-1 and TNF-α in group Ⅱ at 3 h after reperfusion. CONCLUSION: The NO/cGMP pathway may be critical in successful organ transplantation, especially in treat- ing hepatopulmonary syndrome during cold IR injury in rat orthotopic liver transplantation.展开更多
The social organization of marked Helmeted Guineafowl(Numida meleagris) was studied in the Krugersdorp Game Reserve(Gauteng Province,South Africa) during March 1982 to February 1984.Flock members(7-10 guineafowl) did ...The social organization of marked Helmeted Guineafowl(Numida meleagris) was studied in the Krugersdorp Game Reserve(Gauteng Province,South Africa) during March 1982 to February 1984.Flock members(7-10 guineafowl) did not associate randomly.Helmeted Guineafowl must live in a sociable flock to survive in the wild.The highest ranking male(male A) formed the pivot of the daily activities of the flock,such as determining foraging direction.High ranking males(males A and B) associated closely to repulse conspecific intruders.Breeding females associated more often with the high ranking males during the breeding season.Although a pecking order was established among males,the frequency of agonistic actions within the flock was very low,which suggests that agonistic interactions are limited to maintain cohesion.Adult females remained between the dominant male and the juveniles to minimize victimization.The second highest ranking male(B) took center stage while the dominant male and his female left temporarily to breed and then the rest of the flock clustered around him to maintain the cohesive nature of the flock.Most adults assisted with the brooding of the chicks of the highest ranking male.Flocking is,among other functions,a predator surveillance strategy that enables the Helmeted Guineafowl to forage under conditions with very limited ground cover and to maximize food finding during winter.展开更多
A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was diff...A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was difficult to distinguish non-Hodgkin's lymphoma(NHL)invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings.Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1.Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH)identified a translocation of BCL2 with IGHgene. Based on these findings,the tumor was defined as an invasion of FL.T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract,and particularly for the detection of chromosomal translocations specific to lymphoma subtypes.展开更多
The ZM-1 tissue microarrayer designed by our groups is manufactured in stainless steel and brass and contains many features that make TMA (tissue microarray) paraffin blocks construction faster and more convenient. By...The ZM-1 tissue microarrayer designed by our groups is manufactured in stainless steel and brass and contains many features that make TMA (tissue microarray) paraffin blocks construction faster and more convenient. By means of ZM-1 tissue microarrayer, biopsy needles are used to punch the donor tissue specimens respectively. All the needles with the punched specimen cylinders are arrayed into the array-board, with an array of small holes dug to fit the needles. All the specimen cylinders arraying and the TMA paraffin block shaping are finished in only one step so that the specimen cylinders and the paraffin of the TMA block can very easily be incorporated and the recipient paraffin blocks need not be made in advance, and the paraffin used is the same as that for conventional pathology purpose. ZM-1 tissue microarrayer is easy to be manufactured, does not need any precision location system, and so is much cheaper than the currently used instrument. Our method’s relatively cheap and simple ZM-1 tissue microarrayer technique of constructing TMA paraffin block may facilitate popularization of the TMA technology.展开更多
The force model during needle insertion into soft tissue is important for accurate percutaneous intervention.In this paper,a force model for needle insertion into a tissue- equivalent material is presented and a serie...The force model during needle insertion into soft tissue is important for accurate percutaneous intervention.In this paper,a force model for needle insertion into a tissue- equivalent material is presented and a series of experiments are conducted to acquire data from needle soft- tissue interaction process.In order to build a more accurate insertion force model,the interaction force between a surgical needle and soft tissue is divided into three parts:stiffness force,friction force,and cutting force.The stiffness force is modeled on the basis of contact mechanics model.The friction force model is presented using a modified Winkler' s foundation model.The cutting force is viewed as a constant depending on a given tissue.The proposed models in the paper are established on the basis of the mechanical properties and geometric parameters of the needle and soft tissue.The experimental results illustrate that the force models are capable of predicting the needle-tissue interaction force.The force models of needle insertion can provide real-time haptic feedback for robot-assisted procedures,thereby improving the accuracy and safety of surgery.展开更多
AIM: To investigated the interaction between toll-like receptor 4 (TLR4)-activated hepatoma cells and macrophages in the induction of tumor-immune suppression mediated by CD4+CD25high family of transcription factor P3...AIM: To investigated the interaction between toll-like receptor 4 (TLR4)-activated hepatoma cells and macrophages in the induction of tumor-immune suppression mediated by CD4+CD25high family of transcription factor P3 (FOXP3) regulatory T cells (Tregs). METHODS: The proportion of FOXP3+ Tregs was identified in peripheral blood and tumor tissues of 60 hepatocellular carcinoma (HCC) patients. TLR4 expression was examined in tumor tissues and cell lines. The correlation was examined between FOXP3+ Tregs in peripheral blood and TLR4 expression of HCC tissues. Following activation of TLR4 in H22 murine hepatoma cells pre-incubated with lipopolysaccharide (LPS) and co-cultured with macrophage cell line RAW246.7, the synthesis of cytokines tumor necrosis factor-α, CCL22, and interleukin (IL)-10 by the two cell lines was detected and analyzed. RESULTS: FOXP3+ Tregs were enriched in tumor sites, and circulating FOXP3+ Tregs were increased in HCC patients in correlation with multiple tumor foci and up-regulated TLR4 expression in HCC tissues. Semi-quantitative analysis indicated that TLR4 was over-expressed in HCC compared with the matched normal tissues. Cell cultivation experiments indicated that the mRNAs of IL-10 and CCL22 were significantly up-regulated in the RAW246.7 cell line when co-cultured with LPS preincubated H22 cells. CONCLUSION: In hepatoma cell lines, TLR4 may indirectly facilitate the recruitment of Tregs to the tumor site and promote intrahepatic metastasis through its interaction with macrophages.展开更多
Objective To investigate the inhibition of low dose radiation (LDR) on S180 sarcomas and its modulation of MMP-2 and TIMP-2 in mice. Methods $180 subcutaneously implanted tumor model mice were randomly divided into ...Objective To investigate the inhibition of low dose radiation (LDR) on S180 sarcomas and its modulation of MMP-2 and TIMP-2 in mice. Methods $180 subcutaneously implanted tumor model mice were randomly divided into two groups: control (N) and low dose radiation (LDR) groups. N mice were sacrificed after 12 h, whereas LDR mice were sacrificed after 12 (LDR-12 h), 24 (LDR-24 h), 48 (LDR-48 h), and 72 (LDR-72 h) h. Thereafter, we measured the tumor volumes. Histopathology was performed, and P-V immunohistochemistry was applied to assess MMP-2 and TIMP-2 expression. Results Compared with the control group, the tumor growth was significantly inhibited in the LDR groups (P 〈 0.05). MMP-2 expression was considerably reduced in LDR-24h (P 〈 0.05) and LDR-48h (P 〈 0.05), whereas the change of TIMP-2 was not obvious in the LDR groups (P 〉 0.05) in contrast to that of the control group. Conclusion LDR can effectively suppress the growth of S180 implanted tumors by reducing MMP-2, which is associated with invasion and metastasis.展开更多
Family members solve not only their interests, but make provision for interests of other members of the family, too. The space for the control at a higher level is thus formed. Without notifying, individual members in...Family members solve not only their interests, but make provision for interests of other members of the family, too. The space for the control at a higher level is thus formed. Without notifying, individual members in the process of provision making proceed depending on general rules of the organisation of elements into higher structures, as they exist in all stable objects. This provision making has different forms, starting with the love and ending with an assisted coexistence. The understanding of the role of individual controlling structures allows to improve the functioning of the family. Similarly, as a regular discussion of its functioning in the family and perhaps, their controlled casting by some of partners, too. The submitted work describes roles and the control in the elementary family--in the childless coexistence of partners.展开更多
It is of great significance to enhance collaborative community policing for crime prevention and better community-police relationships. Understanding the relational structure of collaborative community policing is nec...It is of great significance to enhance collaborative community policing for crime prevention and better community-police relationships. Understanding the relational structure of collaborative community policing is necessary to pinpoint the pattern of interactions among key actors involved in community policing and improve the effectiveness of network governance. Based on 234 surveys of citizens of S Community in Beijing from April 2017 to May 2017, this paper empirically examines the characteristics of formal network and informal network of citizen participation in the collaborative community policing. Beijing is widely known for its active involvement of neighborhood volunteers in different types of community policing. We focused on four different types of interpersonal work relationships in this study: workflow, problem solving, mentoring and friendship, among resident committees, neighborhood administrative offices, media, police station, business security personnel, neighborhood volunteers, and security activists. The nature of relationships between individuals in networks can be treated as from instrumental ties to expressive ties. Expressive ties cover relationships that involve the exchange of friendship, trust, and socio-emotional support. We extended this intra-organizational insight into a community policing inter-organizational context. The collaborative network showed the trend of the distributed network. The clustering analysis showed that in the workflow network, we should make thll use of the close interaction between the citizens and activists in the community. Meanwhile, in the problem-solving network, mentoring network and friendship network, interactions between citizens and neighborhood committee are weak.展开更多
AZ31B magnesium alloy chips were recycled by three solid-state recycling processes including cold-pressing,hot-pressing followed by hot extrusion and double extrusion.Microstructure and mechanical properties of the re...AZ31B magnesium alloy chips were recycled by three solid-state recycling processes including cold-pressing,hot-pressing followed by hot extrusion and double extrusion.Microstructure and mechanical properties of the recycled specimens and reference specimens were compared.For the recycled specimen by cold-pressing,the grains are refined to a large extent during hot extrusion due to the presence of twins and high density dislocation.The recycled specimens by hot-pressing and double extrusion do not exhibit finer grain than that the recycled specimen by cold-pressing.Consequently,higher ultimate tensile strength of the recycled specimen by hot-pressing and double extrusion is not achieved.For hot pressing process,more compact billet lowers the porosity in recycled material,so elongation to failure of the recycled specimen increases.The recycled specimen fabricated by double extrusion process shows slightly higher elongation than the reference specimen.The second extrusion makes the oxides further crush and distribute more dispersedly,and minimizes porosity,which is responsible for the improved ductility.展开更多
基金Supported by National Science and Technology Support Program(2007BAD38B09)~~
文摘Agricultural cooperative economic organization for water-saving irrigation in arid areas is a new form of economic organization in production,operation and management during the application process of water-saving irrigation technologies.Currently,there are few researches on this cooperative economic organization.In this study,connotations of cooperative economic organizations for water-saving irrigation are specifically defined,and the characteristics and functions of this cooperative economic organization are analyzed.Based on that,several suggestions are proposed on the continuous development of cooperative economic organizations for water-saving irrigation.
基金The National Natural Science Foundation of China(No60473078)
文摘To achieve an on-demand and dynamic composition model of inter-organizational business processes, a new approach for business process modeling and verification is introduced by using the pi-calculus theory. A new business process model which is multi-role, multi-dimensional, integrated and dynamic is proposed relying on inter-organizational collaboration. Compatible with the traditional linear sequence model, the new model is an M x N multi-dimensional mesh, and provides horizontal and vertical formal descriptions for the collaboration business process model. Finally, the pi-calculus theory is utilized to verify the deadlocks, livelocks and synchronization of the example models. The result shows that the proposed approach is efficient and applicable in inter-organizational business process modeling.
文摘The current rural community self-organizing of China is closely related with the rural social stability as well as economic and social development. However, the current rural community self-organizing construction falls far behind the requirements of realistic practice all over China, which greatly affects the advancement of the rural modernization of China. On the other hand, social work provides a unique perspective and method to deal with these problems. Its service philosophy of selfservice as well as its humanitarian value and practical working methods provide reality conformity for the intervention into rural community self-organizing, making it conductive to improving the social relations between rural community residents and possible to realize the mutual development of rural community and rural community residents.
文摘The mechanical properties of Ti-23Al-17Nb (mole fraction,%) laser beam welding alloy joint at room temperature are comparable to that of the base materials.However,the strength and ductility of the as-welded joint deteriorate seriously after high temperature circulation.The effect of post-welded heat treatment on the microstructure and mechanical properties of the joint was investigated.The heat treatment was taken at 980 ℃ for 1.5 h,then furnace cooling and air cooling were performed separately.The results indicate that proper post-welded heat treatment improves the ductility of the joint at high temperature.
基金Project(50725413) supported by the National Natural Science Foundation in ChinaProject(2007CB613704) supported by the National Basic Research Program of China+1 种基金Project(2006AA4012-9-6) supported by the Chongqing Science and Technology Commission,ChinaProject(KJ090628) supported by the Chongqing Education Commission,China
文摘The effects of minor Sr, Sn and Sc addition on the as-cast microstructure and mechanical properties of the ZA84 magnesium alloy were compared. The results indicate that addition of 0.1%Sr, 0.5%Sn or 0.3%Sc (mass fraction) to the ZA84 alloy can refine the grains of the alloy. Furthermore, addition of 0.1%Sr to the ZA84 alloy does not obviously change the morphology and distribution of Mg32(Al,Zn)49 phase. However, addition of 0.5%Sn or 0.3%Sc not only refines and modifies the Mg32(Al,Zn)49 phase but also suppresses the formation of Mg32(Al,Zn)49 phase, especially with the addition of 0.3%Sc. Furthermore, addition of 0.1%Sr, 0.5%Sn or 0.3%Sc to the ZA84 alloy improves the tensile properties at room temperature and 150℃, especially with the addition of 0.1%Sr and 0.3%Sc. However, addition of 0.1%Sr is not beneficial to the creep properties, and addition of 0.5%Sn has no obvious influence on the creep properties. Oppositely, addition of 0.3%Sc to the ZA84 alloy greatly improves the creep properties.
基金support of the Portuguese Foundation for Science and Technology (FCT) through the strategic project UID/Multi/04044/2013the FCT for the doctoral grant SFRH/BD/91151/2012
文摘The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing milieu present in human tissues, and that stimulate tissue repair and regeneration. To be clinically effective, these environments must replicate, as closely as possible, the main characteristics of the native extracellular matrix(ECM) on a cellular and subcellular scale. Photo-fabrication techniques have already been used to generate 3D environments with precise architectures and heterogeneous composition, through a multi-layer procedure involving the selective photocrosslinking reaction of a light-sensitive prepolymer. Cells and therapeutic molecules can be included in the initial hydrogel precursor solution, and processed into 3D constructs. Recently, photofabrication has also been explored to dynamically modulate hydrogel features in real time, providing enhanced control of cell fate and delivery of bioactive compounds. This paper focuses on the use of 3D photo-fabrication techniques to produce advanced constructs for tissue regeneration and drug delivery applications. State-of-the-art photo-fabrication techniques are described, with emphasis on the operating principles and biofabrication strategies to create spatially controlled patterns of cells and bioactive factors. Considering its fast processing, spatiotemporal control, high resolution, and accuracy, photo-fabrication is assuming a critical role in the design of sophisticated 3D constructs. This technology is capable of providing appropriate environments for tissue regeneration, and regulating the spatiotemporal delivery of therapeutics.
文摘This study addresses current status of ESSQ management and integration in steel production organisation. The idea is to benchmark maturity levels with the leading Finnish international companies. The examination has been done in compliance with applied maturity model developed by the target corporation. When examining the benchmarked companies through the ESSQ framework, we found that a similar framework cannot be found in any other company as such; instead, operations are distributed under different organisations. Although many sources criticise system-based development, the results of this study indicate that it is nevertheless an efficient way to develop operations.
基金financially supported by Grants from Qingdao Technology Office, Qingdao Technology Developing Plan, 10-3-3-3-11-NSH and 03-3-hh-09
文摘Oyster extract is an effective bioactivity component. It has abundant nutritional value and antiviral, antitumor and im- mune defense fimctions. The role of oyster extract in treating liver injury has been paid more attention. We use Wistar rats to make alcoholic liver disease model through injecting alcohol into rats' stomachs. These rats were randomly divided into five groups: model group, control group, low-dose, middle-dose and high-dose experimental group with a dose of 0.12gkg-1, 0.40gkg-1, and 1.20gkg-1 alcoholic. After nine weeks, serum biomarkers (ALT, AST, TG and TCHO), malondialdehyde (MDA), glutathione (GSH), C3a, CSa, IL-17, TNF-a, anti-MAA-HAS IgC~ CD3+, CD4+, CDS+, NK cell activation and zinc content were assessed. The results showed that the serum biomarkers(ALT, AST, TG and TCHO), MDA content, anti-MAA-HSA IgG, serum C3a, CSa IL-17 and TNF-a levels of oyster extract treatment groups were significantly decreased in comparison with model group. On the contrary, GSH showed ad- verse trend. Serum CD3+, CD4+ and NK cell activation were significantly increased in middle-dose group and high-dose group compared with model group, and there was decrease of CD8+ activity in high-dose group. Plasma Zn level was decreased in model group compared with that in control group. Meanwhile, Mean plasma Zn levels increased dramatically following the dose increase of a given oyster extract.
文摘AIM: To evaluate immunological protection of nitric ox- ide (NO) in hepatopulmonary syndrome and probable mechanisms of ischemia-reperfusion (IR) injury in rat liver transplantation, METHODS: Sixty-six healthy male Wistar rats were randomly divided into three groups (11 donor/recipi-ent pairs). In group 11, organ preservation solution was lactated Ringer's solution with heparin 10 000/μL at 4℃. In groups I and 111, the pLeservation solution added, respectively, L-arginine or Ng-L-arginine methyl ester (L-NAME) (1 mmol/L) based on group 11, and recipients were injected with L-arginine or L-NAME (50 mg/kg) in the anhepatic phase. Grafted livers in each group were stored for 6 h and implanted into recipi- ents. Five rats were used for observation of postopera- tive survival in each group. The other six rats in each group were used to obtain tissue samples, and execut- ed at 3 h and 24 h after transplantation. The levels of alanine aminotransferase (ALT), tumor necrosis factor (TNF)-a and NO metabolites (NOx) were detected, and expression of NO synthase, TNF-α and intercellular adhesion molecule 1 (ICAM-1) was examined by tri- phosphopyridine nucleotide diaphorase histochemical and immunohistochemical staining. RESULTS: By supplementing L-arginine to strengthen the NO pathway, a high survival rate was achieved and hepatic function was improved. One-week sur- viral rate of grafted liver recipients in group I was significantly increased (28.8 4±36.6 d ys 4 4±1.7 d, P 〈 0.01) as compared with groups 11 and Ill. Serum levels of ALT in group ] were 2-7 times less than those in groups 11 and 11I (P 〈 0.01). The cyclic guanosine monophosphate (cGMP) levels in liver tissue and NOx in group I were 3-4 times higher than those of group 11 after 3 h and 24 h reperfusion, while in group ]]], they were significantly reduced as compared with those in group ]1 (P 〈 0.01). The levels of TNF-(z in group I were significantly lower than in group Ⅱ after 3 h and 24 h reperfusion (P 〈 0.01), while being sig- nificantly higher in group Ⅲ than group Ⅱ (P 〈 0.01). Histopathology revealed more severe tissue damage in graft liver and lung tissues, and a more severe in- flammatory response of the recipient after using NO synthase inhibitor, while the pathological damage to grafted liver and the recipient's lung tissues was signifi-cantly reduced in group I after 3 h and 24 h reperfu- sion. A small amount of constitutive NO synthase (cNOS) was expressed in liver endothelial cells after 6 h cold storage, but there was no expression of inducible NO synthase (iNOS). Expression of cNOS was particularly significant in vascular endothelial cells and liver cells at 3 h and 24 h after reperfusion in group Ⅱ but expres- sion of iNOS and ICAM-1 was low in group I. There was diffuse strong expression of ICAM-1 and TNF-α in group Ⅱ at 3 h after reperfusion. CONCLUSION: The NO/cGMP pathway may be critical in successful organ transplantation, especially in treat- ing hepatopulmonary syndrome during cold IR injury in rat orthotopic liver transplantation.
文摘The social organization of marked Helmeted Guineafowl(Numida meleagris) was studied in the Krugersdorp Game Reserve(Gauteng Province,South Africa) during March 1982 to February 1984.Flock members(7-10 guineafowl) did not associate randomly.Helmeted Guineafowl must live in a sociable flock to survive in the wild.The highest ranking male(male A) formed the pivot of the daily activities of the flock,such as determining foraging direction.High ranking males(males A and B) associated closely to repulse conspecific intruders.Breeding females associated more often with the high ranking males during the breeding season.Although a pecking order was established among males,the frequency of agonistic actions within the flock was very low,which suggests that agonistic interactions are limited to maintain cohesion.Adult females remained between the dominant male and the juveniles to minimize victimization.The second highest ranking male(B) took center stage while the dominant male and his female left temporarily to breed and then the rest of the flock clustered around him to maintain the cohesive nature of the flock.Most adults assisted with the brooding of the chicks of the highest ranking male.Flocking is,among other functions,a predator surveillance strategy that enables the Helmeted Guineafowl to forage under conditions with very limited ground cover and to maximize food finding during winter.
文摘A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphoma(FL).Colonoscopic examination revealed a rectal submucosal tumor(SMT)without any erosions and ulcers.In this patient,it was difficult to distinguish non-Hodgkin's lymphoma(NHL)invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings.Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1.Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH)identified a translocation of BCL2 with IGHgene. Based on these findings,the tumor was defined as an invasion of FL.T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract,and particularly for the detection of chromosomal translocations specific to lymphoma subtypes.
基金Project (No. G1998051200) supported by the National Basic Re-search Program (973) of China
文摘The ZM-1 tissue microarrayer designed by our groups is manufactured in stainless steel and brass and contains many features that make TMA (tissue microarray) paraffin blocks construction faster and more convenient. By means of ZM-1 tissue microarrayer, biopsy needles are used to punch the donor tissue specimens respectively. All the needles with the punched specimen cylinders are arrayed into the array-board, with an array of small holes dug to fit the needles. All the specimen cylinders arraying and the TMA paraffin block shaping are finished in only one step so that the specimen cylinders and the paraffin of the TMA block can very easily be incorporated and the recipient paraffin blocks need not be made in advance, and the paraffin used is the same as that for conventional pathology purpose. ZM-1 tissue microarrayer is easy to be manufactured, does not need any precision location system, and so is much cheaper than the currently used instrument. Our method’s relatively cheap and simple ZM-1 tissue microarrayer technique of constructing TMA paraffin block may facilitate popularization of the TMA technology.
基金Supported by the National Natural Science Foundation of China(No.51175373)New Century Educational Talents Plan of Chinese Education Ministry(No.NCET-10-0625)+1 种基金Key Technology and Development Program of Tianjin Municipal Science and Technology Commission(No.12ZCDZSY10600)Tianjin Key Laboratory of High Speed Cutting&Precision Machining(TUTE)(2013120024001167)
文摘The force model during needle insertion into soft tissue is important for accurate percutaneous intervention.In this paper,a force model for needle insertion into a tissue- equivalent material is presented and a series of experiments are conducted to acquire data from needle soft- tissue interaction process.In order to build a more accurate insertion force model,the interaction force between a surgical needle and soft tissue is divided into three parts:stiffness force,friction force,and cutting force.The stiffness force is modeled on the basis of contact mechanics model.The friction force model is presented using a modified Winkler' s foundation model.The cutting force is viewed as a constant depending on a given tissue.The proposed models in the paper are established on the basis of the mechanical properties and geometric parameters of the needle and soft tissue.The experimental results illustrate that the force models are capable of predicting the needle-tissue interaction force.The force models of needle insertion can provide real-time haptic feedback for robot-assisted procedures,thereby improving the accuracy and safety of surgery.
文摘AIM: To investigated the interaction between toll-like receptor 4 (TLR4)-activated hepatoma cells and macrophages in the induction of tumor-immune suppression mediated by CD4+CD25high family of transcription factor P3 (FOXP3) regulatory T cells (Tregs). METHODS: The proportion of FOXP3+ Tregs was identified in peripheral blood and tumor tissues of 60 hepatocellular carcinoma (HCC) patients. TLR4 expression was examined in tumor tissues and cell lines. The correlation was examined between FOXP3+ Tregs in peripheral blood and TLR4 expression of HCC tissues. Following activation of TLR4 in H22 murine hepatoma cells pre-incubated with lipopolysaccharide (LPS) and co-cultured with macrophage cell line RAW246.7, the synthesis of cytokines tumor necrosis factor-α, CCL22, and interleukin (IL)-10 by the two cell lines was detected and analyzed. RESULTS: FOXP3+ Tregs were enriched in tumor sites, and circulating FOXP3+ Tregs were increased in HCC patients in correlation with multiple tumor foci and up-regulated TLR4 expression in HCC tissues. Semi-quantitative analysis indicated that TLR4 was over-expressed in HCC compared with the matched normal tissues. Cell cultivation experiments indicated that the mRNAs of IL-10 and CCL22 were significantly up-regulated in the RAW246.7 cell line when co-cultured with LPS preincubated H22 cells. CONCLUSION: In hepatoma cell lines, TLR4 may indirectly facilitate the recruitment of Tregs to the tumor site and promote intrahepatic metastasis through its interaction with macrophages.
文摘Objective To investigate the inhibition of low dose radiation (LDR) on S180 sarcomas and its modulation of MMP-2 and TIMP-2 in mice. Methods $180 subcutaneously implanted tumor model mice were randomly divided into two groups: control (N) and low dose radiation (LDR) groups. N mice were sacrificed after 12 h, whereas LDR mice were sacrificed after 12 (LDR-12 h), 24 (LDR-24 h), 48 (LDR-48 h), and 72 (LDR-72 h) h. Thereafter, we measured the tumor volumes. Histopathology was performed, and P-V immunohistochemistry was applied to assess MMP-2 and TIMP-2 expression. Results Compared with the control group, the tumor growth was significantly inhibited in the LDR groups (P 〈 0.05). MMP-2 expression was considerably reduced in LDR-24h (P 〈 0.05) and LDR-48h (P 〈 0.05), whereas the change of TIMP-2 was not obvious in the LDR groups (P 〉 0.05) in contrast to that of the control group. Conclusion LDR can effectively suppress the growth of S180 implanted tumors by reducing MMP-2, which is associated with invasion and metastasis.
文摘Family members solve not only their interests, but make provision for interests of other members of the family, too. The space for the control at a higher level is thus formed. Without notifying, individual members in the process of provision making proceed depending on general rules of the organisation of elements into higher structures, as they exist in all stable objects. This provision making has different forms, starting with the love and ending with an assisted coexistence. The understanding of the role of individual controlling structures allows to improve the functioning of the family. Similarly, as a regular discussion of its functioning in the family and perhaps, their controlled casting by some of partners, too. The submitted work describes roles and the control in the elementary family--in the childless coexistence of partners.
文摘It is of great significance to enhance collaborative community policing for crime prevention and better community-police relationships. Understanding the relational structure of collaborative community policing is necessary to pinpoint the pattern of interactions among key actors involved in community policing and improve the effectiveness of network governance. Based on 234 surveys of citizens of S Community in Beijing from April 2017 to May 2017, this paper empirically examines the characteristics of formal network and informal network of citizen participation in the collaborative community policing. Beijing is widely known for its active involvement of neighborhood volunteers in different types of community policing. We focused on four different types of interpersonal work relationships in this study: workflow, problem solving, mentoring and friendship, among resident committees, neighborhood administrative offices, media, police station, business security personnel, neighborhood volunteers, and security activists. The nature of relationships between individuals in networks can be treated as from instrumental ties to expressive ties. Expressive ties cover relationships that involve the exchange of friendship, trust, and socio-emotional support. We extended this intra-organizational insight into a community policing inter-organizational context. The collaborative network showed the trend of the distributed network. The clustering analysis showed that in the workflow network, we should make thll use of the close interaction between the citizens and activists in the community. Meanwhile, in the problem-solving network, mentoring network and friendship network, interactions between citizens and neighborhood committee are weak.
基金Projects(50674038,50974048) supported by the National Natural Science Foundation of ChinaProject(11541347) supported by the Educational Office of Heilongjiang Province,China
文摘AZ31B magnesium alloy chips were recycled by three solid-state recycling processes including cold-pressing,hot-pressing followed by hot extrusion and double extrusion.Microstructure and mechanical properties of the recycled specimens and reference specimens were compared.For the recycled specimen by cold-pressing,the grains are refined to a large extent during hot extrusion due to the presence of twins and high density dislocation.The recycled specimens by hot-pressing and double extrusion do not exhibit finer grain than that the recycled specimen by cold-pressing.Consequently,higher ultimate tensile strength of the recycled specimen by hot-pressing and double extrusion is not achieved.For hot pressing process,more compact billet lowers the porosity in recycled material,so elongation to failure of the recycled specimen increases.The recycled specimen fabricated by double extrusion process shows slightly higher elongation than the reference specimen.The second extrusion makes the oxides further crush and distribute more dispersedly,and minimizes porosity,which is responsible for the improved ductility.