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Abstract The rapid evolution of clinical medicine, materials science, and regenerative medicine has rendered traditional implantable scaffolds inadequate for addressing the complex therapeutic demands of various diseases. Currently, implantable scaffolds in clinical practice are mainly made of metal, with the disadvantages of high stiffness, poor toughness, and low deformation. This paper offers a thorough review of shape memory scaffolds (SMSs), emphasizing their distinctive self‐recovery and adaptive functionalities that enhance compatibility with injured tissues, surpassing the capabilities of conventional metallic biomaterials. It delves into the limitations of current clinical scaffolds and the requisite performance metrics for effective implants and outlines the essential materials and fabrication methods for SMSs. Moreover, we enumerate the biomedical applications of SMMs with different response types, including thermology‐responsive, water‐responsive, and light‐responsive. The discussion extends to the burgeoning applications of SMSs in biomedical engineering, including their utility in bone tissue engineering, cardiovascular stenting, tubular structures, and cardiac patches, which underscore their potential in minimally invasive procedures and dynamic tissue interactions. This review concludes with an analysis of current challenges and prospects, providing valuable insights for developing and applying SMSs in the biomedical sector.

Abstract Data clustering has attracted the interest of scholars in many fields. In recent years, using heuristic algorithms to solve data clustering problems has gradually become a tendency. The black hole algorithm (BHA) is one of the popular heuristic algorithms among researchers because of its simplicity and effectiveness. In this paper, an improved self-adaptive logarithmic spiral path black hole algorithm (SLBHA) is proposed. SLBHA innovatively introduces a logarithmic spiral path and random vector path to BHA. At the same time, a parameter is used to control the randomness, which enhances the local exploitation ability of the algorithm. Besides, SLBHA designs a replacement mechanism to improve the global exploration ability. Finally, a self-adaptive parameter is introduced to control the replacement mechanism and maintain the balance between exploration and exploitation of the algorithm. To verify the effectiveness of the proposed algorithm, comparison experiments are conducted on 13 datasets creatively using the evaluation criteria including the Jaccard coefficient as well as the Folkes and Mallows index. The proposed methods are compared with the selected algorithms such as the whale optimization algorithm (WOA), compound intensified exploration firefly algorithm (CIEFA), improved black hole algorithm (IBH), etc. The experimental results demonstrate that the proposed algorithm outperforms the compared algorithms on both external criteria and quantization error of the clustering problem.

Abstract Background Potentially inappropriate prescribing is common among older adults with multimorbidity due to various reasons, from concurrent application of multiple single-disease clinical guidelines to fragmentation of care. Interventions such as medication review have been implemented worldwide to reduce inappropriate prescribing for older adults. However, the implementability of such interventions are underexplored in the outpatient clinics in Singapore’s public hospitals. Hence, the Pro-M study aims to assess the feasibility of implementing a physician-pharmacist collaborative care intervention in geriatric medicine outpatient clinics to facilitate appropriate prescribing for older adults in Singapore. Methods This is a single-arm, non-randomised feasibility study using a pre-post evaluation design. This study consists of two parts: (1) implementation phase of the intervention (6 months) and an (2) evaluation phase (3 months). Eligible patients will be recruited from geriatric medicine outpatient clinics at two public hospitals in Singapore through convenience sampling. The main components of the Pro-M intervention are: (1) pharmacist-facilitated medication reviews with feedback on any medication issues and potential recommendations to physicians, and (2) physicians communicating changes to other relevant prescribers. The evaluation phase will involve surveying and interviewing physicians and pharmacists involved in the implementation of the intervention. A mixed-method approach will be employed for data collection and analysis. The quantitative and qualitative findings will be triangulated and reported using Proctor’s implementation outcomes: appropriateness, penetration, acceptability, fidelity, feasibility, and sustainability. A basic cost analysis will be conducted alongside the study. Discussion This is a phase 2 study to test the feasibility of implementing an intervention that was co-created with stakeholders during phase 1 development of an intervention to optimise prescribing for older adults with multimorbidity. The implementation will be assessed using Proctor’s implementation outcomes to provide insights on the process and the feasibility of implementing medication reviews for older adults with multimorbidity as a routine practice in outpatient clinics. Data collected from this study will inform a subsequent scale-up study. Trial registration ClinicalTrials.gov Identifier: NCT05756478. Registered on 06 March 2023.

Abstract The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone‐regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue‐engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Computer networks have touched every aspect of human life, it cannot be overstated that cyber security is of great importance and significance. Intrusion detection techniques play an important role in the field of network security, but it also faces significant challenges. In this paper, we propose a Hybrid Firefly and Black Hole Algorithm (HFBHA) for parameter tuning of the XGBoost model and apply it to the study of intrusion detection systems. Firstly, the algorithm designs a double black hole mechanism by introducing the concept of the second black hole and adjusting the moving trajectory of the stars using the attraction of both black holes. Secondly, an improved initialization method of the stars is proposed, where a star that crosses the event horizon of the black hole has an opportunity to be replaced by a new star around the black hole. Finally, a combination of the firefly perturbation strategy and mutation operator is proposed to improve the global search capability of the algorithm. Both the effectiveness of the proposed method on the XBGoost parameter tuning problem and the feasibility of this strategy on intrusion detection applications are verified by comparison experiments based on the NSL-KDD dataset.

The clinical challenge of bone defects in the craniomaxillofacial region, which can lead to significant physiological dysfunction and psychological distress, persists due to the complex and unique anatomy of craniomaxillofacial bones. These critical-sized defects require the use of bone grafts or substitutes for effective reconstruction. However, current biomaterials and methods have specific limitations in meeting the clinical demands for structural reinforcement, mechanical support, exceptional biological performance, and aesthetically pleasing reconstruction of the facial structure. These drawbacks have led to a growing need for novel materials and technologies. The growing development of 3D printing can offer significant advantages to address these issues, as demonstrated by the fabrication of patient-specific bioactive constructs with controlled structural design for complex bone defects in medical applications using this technology. Poly (ether ether ketone) (PEEK), among a number of materials used, is gaining recognition as a feasible substitute for a customized structure that closely resembles natural bone. It has proven to be an excellent, conformable, and 3D-printable material with the potential to replace traditional autografts and titanium implants. However, its biological inertness poses certain limitations. Therefore, this review summarizes the distinctive features of craniomaxillofacial bones and current methods for bone reconstruction, and then focuses on the increasingly applied 3D printed PEEK constructs in this field and an update on the advanced modifications for improved mechanical properties, biological performance, and antibacterial capacity. Exploring the potential of 3D printed PEEK is expected to lead to more cost-effective, biocompatible, and personalized treatment of craniomaxillofacial bone defects in clinical applications.

Abstract Cells interact with their surrounding environment through a combination of static and dynamic mechanical signals that vary over stimulus types, intensity, space, and time. Compared to static mechanical signals such as stiffness, porosity, and topography, the current understanding on the effects of dynamic mechanical stimulations on cells remains limited, attributing to a lack of access to devices, the complexity of experimental set‐up, and data interpretation. Yet, in the pursuit of emerging translational applications (e.g., cell manufacturing for clinical treatment), it is crucial to understand how cells respond to a variety of dynamic forces that are omnipresent in vivo so that they can be exploited to enhance manufacturing and therapeutic outcomes. With a rising appreciation of the extracellular matrix (ECM) as a key regulator of biofunctions, researchers have bioengineered a suite of ECM‐mimicking hydrogels, which can be fine‐tuned with spatiotemporal mechanical cues to model complex static and dynamic mechanical profiles. This review first discusses how mechanical stimuli may impact different cellular components and the various mechanobiology pathways involved. Then, how hydrogels can be designed to incorporate static and dynamic mechanical parameters to influence cell behaviors are described. The Scopus database is also used to analyze the relative strength in evidence, ranging from strong to weak, based on number of published literatures, associated citations, and treatment significance. Additionally, the impacts of static and dynamic mechanical stimulations on clinically relevant cell types including mesenchymal stem cells, fibroblasts, and immune cells, are evaluated. The aim is to draw attention to the paucity of studies on the effects of dynamic mechanical stimuli on cells, as well as to highlight the potential of using a cocktail of various types and intensities of mechanical stimulations to influence cell fates (similar to the concept of biochemical cocktail to direct cell fate). It is envisioned that this progress report will inspire more exciting translational development of mechanoresponsive hydrogels for biomedical applications.

Abstract SARS‐CoV‐2 is an enveloped positive‐sense RNA virus that depends on host factors for all stages of its life. Membrane receptor ACE2 is a well‐established factor for SARS‐CoV‐2 docking. In addition to ACE2, whole‐genome genetic screens have identified additional proteins, such as endosomal trafficking regulators SNX27 and retromer, as key host factors required for SARS‐CoV‐2 infection. However, it is poorly understood how SARS‐CoV‐2 utilize host endocytic transport pathways to produce productive infection. Here, we report that SNX27 interacts with the SARS‐CoV‐2 spike (S) protein to facilitate S protein surface expression. Interestingly, S protein binds to the PDZ domain of SNX27, although it does not contain a PDZ‐binding motif (PDZbm). Either abrogation of the SNX27 PDZ domain or S protein “MTSC” motif, which is critical for SNX27 binding, decreases surface expression of S protein and viral production. Collectively, our study highlights a novel approach utilized by SARS‐CoV‐2 to facilitate virion trafficking to establish virus infection.

Abstract Autonomous motion and motility are hallmarks of active matter. Active agents, such as biological cells and synthetic colloidal particles, consume internal energy or extract energy from the environment to generate self-propulsion and locomotion. These systems are persistently out of equilibrium due to continuous energy consumption. It is known that pressure is not always a state function for generic active matter. Torque interaction between active constituents and confinement renders the pressure of the system a boundary-dependent property. The mechanical pressure of anisotropic active particles depends on their microscopic interactions with a solid wall. Using self-propelled dumbbells confined by solid walls as a model system, we perform numerical simulations to explore how variations in the wall stiffness influence the mechanical pressure of dry active matter. In contrast to previous findings, we find that mechanical pressure can be independent of the interaction of anisotropic active particles with walls, even in the presence of intrinsic torque interaction. Particularly, the dependency of pressure on the wall stiffness vanishes when the stiffness is above a critical level. In such a limit, the dynamics of dumbbells near the walls are randomized due to the large torque experienced by the dumbbells, leading to the recovery of pressure as a state variable of density.

BackgroundThe rapid spread of the coronavirus disease 2019 (COVID-19) pandemic has caused people to worry, which has affected their mental health. This study aimed to access the impact of COVID-19 worry on the mental health of the economically active population (EAP) in a province of China.MethodsAn online cross-sectional survey study was conducted during an outbreak of COVID-19 in Guangdong, China. The survey used the 12-item General Health Questionnaire (GHQ-12) to evaluate participants' mental health status and was completed by 1,584 of the 1,708 participants (a response rate of 92.74%). Ordinary least squares (OLS) regression models were used to identify the correlation between COVID-19 worry and mental health.ResultsApproximately 42.05% of participants reported that they were very worried or extremely worried about the COVID-19 pandemic. COVID-19 worry was negatively correlated with mental health (p < 0.01) and exhibited a stronger influence on the mental health of participants who were male, younger (aged 16–45), or unemployed than on the mental health of participants who were women, older (aged over 45), or employed.ConclusionThe findings suggest that COVID-19 worry has generated new inequalities in mental health among the EAP of China. The government should provide more public reassurance and psychological support to the EAP to mitigate the effects of COVID-19 worry and prevent mental health disorders.

Summary: Complex mechanisms govern the sorting of membrane (cargo) proteins at endosomes to ensure that protein localization to the post-Golgi endomembrane system is accurately maintained. Endosomal retrieval complexes mediate sorting by recognizing specific motifs and signals in the cytoplasmic domains of cargo proteins transiting through endosomes. In this review, the recent progress in understanding the molecular mechanisms of how the retromer complex, in conjunction with sorting nexin (SNX) proteins, operates in cargo recognition and sorting is discussed. New data revealing the importance of different SNX proteins and detailing how post-translational modifications can modulate cargo sorting to respond to changes in the environment are highlighted along with the key role that endosomal protein sorting plays in SARS-CoV-2 infection.

Background and AimsEmergency endoscopy is recommended for patients with acute esophageal variceal bleeding (EVB) and their prognosis has improved markedly over past decades due to the increased specialization of endoscopic practice. The study aimed to compare outcomes following emergency endoscopic injection sclerotherapy (EIS) and endoscopic variceal ligation (EVL) in cirrhotic patients with acute EVB.MethodsCirrhotic patients with acute EVB who underwent emergency endoscopy were retrospectively enrolled from 2013 to 2020 across 34 university hospitals from 30 cities. The primary outcome was the incidence of 5-day rebleeding after emergency endoscopy. Subgroup analysis was stratified by Child-Pugh class and bleeding history. A 1:1 propensity score matching (PSM) analysis was performed.ResultsA total of 1,017 and 382 patients were included in EIS group and EVL group, respectively. The 5-day rebleeding incidence was similar between EIS group and EVL group (4% vs. 5%, P = 0.45). The result remained the same after PSM (P = 1.00). Among Child-Pugh class A, B and C patients, there were no differences in the 5-day rebleeding incidence between the two groups after PSM (P = 0.25, 0.82, and 0.21, respectively). As for the patients with or without bleeding history, the differences between EIS group and EVL group were not significant after PSM (P = 1.00 and 0.26, respectively).ConclusionThe nationwide cohort study indicates that EIS and EVL are both efficient emergency endoscopic treatment strategies for acute EVB. EIS should not be dismissed as an economical and effective emergency endoscopic treatment strategy of acute EVB. ClincialTrials.gov number NCT04307264.

Using the apparent magnitude-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 10, we examine the K-band luminosity–density relation at fixed parameters or for different galaxy families. It is found that the limiting or fixing galaxy properties, such as galaxy morphology, stellar mass, and color, exert substantial influence on the environmental dependence of the K-band luminosity of galaxies, which suggests that the K-band luminosity–density relation is likely attributable to the relation between these galaxy properties and density.

Inter-nuclear ophthalmoplegia (INO) may not always have overt or obvious clinical signs during bedside examination. In patients presenting with mild/subtle INO with no focal neurological deficits or cerebellar signs, an unremarkable radiographic imaging and blood work, diagnosis will be challenging. Results of bedside head thrust tests will also be confounded and difficult to interpret, leading to discordant impressions among physicians of different specialties. Patients with mild INO will still require active surveillance to watch for any progression and development of clinical signs and should be managed by neuro-ophthalmology specialty. Video-oculography can assist with the interpretation of bedside head thrust and reveal slowing of adduction that is otherwise not obvious bedside. This has downstream implications on the management of patients with mild INO as they may be “volleyed” among different medical specialties if covert bedside signs are overlooked. Greater caution is needed on interpreting positive head thrust/video head impulse test as a peripheral vestibular sign in the presence of disconjugate oculomotor movements. Patients with mild INO may be relatively asymptomatic but may still have some functional impairments that should be addressed appropriately.

Porous polycaprolactone (PCL) bone scaffolds were prepared by selective laser sintering and chitosan/hydroxyapatite(CS/HA) suspension was prepared by in situ synthesis. The CS/HA was attached to the surface of the PCL scaffold by vacuum immersion, low speed centrifugation and freezing gel, to improve the biocompatibility and cell proliferation activity of the PCL scaffolds. The phase and porous structure of the composite scaffolds were observed by X ray diffraction (XRD) and scanning electron microscopy (SEM). The compressive strength and Young's modulus of the scaffolds were measured, the water contact angles on the surface of the scaffolds were measured and the biological properties of the composite scaffolds were studied by in vitro cell experiments. The experimental results show that hydroxyapatite (HA) is prepared by in situ synthesis, and CS/HA gel adhered well to the surface of PCL bone scaffold. The hydrophilicity of the surface of the PCL scaffold is improved by CS/HA, and the biocompatibility and cell proliferation activity of them are greatly enhanced.

Developing efficient N2 and O2 gas sensors is of great importance to our daily life and industrial technology. In this work, first-principles calculations are performed to study the N2 and O2 gas-sensing properties of pure and defected PtSe2. It is found that both N2 and O2 adsorb weakly on pure PtSe2, and adsorption of the molecules induces negligible changes in the electrical and optical properties. Whereas the Pt@Se anti-site defect significantly improves the N2 adsorption capacity of PtSe2 and induces notable changes in the electrical property. Similar results are also observed for the Pt and Se vacancies and Pt@Se anti-site defects when examining O2 adsorption. In addition, notable changes in the optical absorption spectra of the PtSe2 with Pt@Se defect are induced upon N2 adsorption, which also occurs for PtSe2 with Pt and Se vacancies and Pt@Se anti-site defects upon O2 adsorption. These results demonstrate that PtSe2 with the corresponding defects can be both excellent electrical and optical sensors for detecting N2 and O2 gases. Our work offers a new avenue for preparing efficient gas sensors.

Endosomes are essential cellular stations where endocytic and secretory trafficking routes converge. Proteins transiting at endosomes can be degraded via lysosome, or recycled to the plasma membrane, trans-Golgi network (TGN), or other cellular destinations. Pathways regulating endosomal recycling are tightly regulated in order to preserve organelle identity, to maintain lipid homeostasis, and to support other essential cellular functions. Recent studies have revealed that both pathogenic bacteria and viruses subvert host endosomal recycling pathways for their survival and replication. Several host factors that are frequently targeted by pathogens are being identified, including retromer, TBC1D5, SNX-BARs, and the WASH complex. In this review, we will focus on the recent advances in understanding how intracellular bacteria, human papillomavirus (HPV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hijack host endosomal recycling pathways. This exciting work not only reveals distinct mechanisms employed by pathogens to manipulate host signaling pathways, but also deepens our understanding of the molecular intricacies regulating endosomal receptor trafficking.

Endocytic recycling of internalized transmembrane proteins is essential for many important physiological processes. Recent studies have revealed that retromer-related Sorting Nexin family (SNX)-Bin/Amphiphysin/Rvs (BAR) proteins can directly recognize cargoes like cation-independent mannose 6-phosphate receptor (CI-MPR) and Insulin-like growth factor 1 receptor (IGF1R); however, it remains poorly understood how SNX-BARs select specific cargo proteins and whether they recognize additional ligands. Here, we discovered that the binding between SNX-BARs and CI-MPR or IGF1R is mediated by the phox-homology (PX) domain of SNX5 or SNX6 and a bipartite motif, termed SNX-BAR-binding motif (SBM), in the cargoes. Using this motif, we identified over 70 putative SNX-BAR ligands, many of which play critical roles in apoptosis, cell adhesion, signal transduction, or metabolite homeostasis. Remarkably, SNX-BARs could cooperate with both SNX27 and retromer in the recycling of ligands encompassing the SBM, PDZ-binding motif, or both motifs. Overall, our studies establish that SNX-BARs function as a direct cargo-selecting module for a large set of transmembrane proteins transiting the endosome, in addition to their roles in phospholipid recognition and biogenesis of tubular structures.

The Coronavirus Disease 2019 (COVID-19) has swept the whole world with high mortality. Since droplet transmission is the main route of transmission, wearing a mask serves as a crucial preventive measure. However, the virus has spread quite quickly, causing severe mask shortage. Finding alternative materials for homemade masks while ensuring the significant performance indicators will help alleviate the shortage of masks. Referring to the national standard for the "Surgical Mask" of China, 17 materials to be selected for homemade masks were tested in four key indicators: pressure difference, particle filtration efficiency, bacterial filtration efficiency and resistance to surface wetting. Eleven single-layer materials met the standard of pressure difference (≤49 Pa), of which 3 met the standard of resistance to surface wetting (≥3), 1 met the standard of particle filtration efficiency (≥30%), but none met the standard of bacterial filtration efficiency (≥95%). Based on the testing results of single-layer materials, fifteen combinations of paired materials were tested. The results showed that three double-layer materials including double-layer medical non-woven fabric, medical non-woven fabric plus non-woven shopping bag, and medical non-woven fabric plus granular tea towel could meet all the standards of pressure difference, particle filtration efficiency, and resistance to surface wetting, and were close to the standard of the bacterial filtration efficiency. In conclusion, if resources are severely lacking and medical masks cannot be obtained, homemade masks using available materials, based on the results of this study, can minimize the chance of infection to the maximum extent.

In solving classification problems in the field of machine learning and pattern recognition, the pre-processing of data is particularly important. The processing of high-dimensional feature datasets increases the time and space complexity of computer processing and reduces the accuracy of classification models. Hence, the proposal of a good feature selection method is essential. This paper presents a new algorithm for solving feature selection, retaining the selection and mutation operators from traditional genetic algorithms. On the one hand, the global search capability of the algorithm is ensured by changing the population size, on the other hand, finding the optimal mutation probability for solving the feature selection problem based on different population sizes. During the iteration of the algorithm, the population size does not change, no matter how many transformations are made, and is the same as the initialized population size; this spatial invariance is physically defined as symmetry. The proposed method is compared with other algorithms and validated on different datasets. The experimental results show good performance of the algorithm, in addition to which we apply the algorithm to a practical Android software classification problem and the results also show the superiority of the algorithm.

Nano-injection molding technology is an important method for large-scale production of metal-polymer composites of various shapes. The mechanical properties of these materials are closely related to the interfacial process. In this work, polyphenylene sulfide (PPS) and copper (Cu) were selected as candidate polymer and metal materials, and constructed four different polydopamine (PDA) coatings, including monomer, dimer, linear tetramer, and cyclic tetramer, to modify metal surfaces. The molecular dynamics simulations were launched to investigate the interaction behavior of heterogeneous interfaces during nano-injection molding and the mechanism by which polydopamine affects the adhesion behavior at the copper-polyphenylene sulfide interface. Results showed that the addition of polydopamine caused the polymer chains to form many anchor points on the contact surface, which inhibited the wall-slip behavior of the polymer and led to a mushroom-like movement of the polymer on the wall surface. The interfacial energy, filling rate data revealed that polydopamine contributes to the enhancement of interfacial adhesion properties, and the polydopamine dimer structure is the most effective of the four configurations. The enhancement of interfacial adhesion mainly originates from the enhancement of non-bonding interactions and entanglement anchoring between PPS-PDA. Highlights * Polydopamine coating inhibits polymer slip behavior in nano-injection molding. * Polydopamine enhances bond strength of metal-polymer composites effectively. * Dopamine dimers have better adhesion properties than other structural dopamine. * Polydopamine coating alters the adhesion mechanism at heterogeneous interfaces. * The interface failure mode was closely related to the stress loading mode. KEYWORDS anchoring behaviors, Interface, molecular dynamics simulation, nano-injection molding, polydopamine, 1 | INTRODUCTION With the rapid advancements in micro and nanotechnology, there has been a increasing demand for the production of miniaturized and precisely engineered products. The concept of 'micro' [...]

The apparent magnitude-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 7 is used to investigate the environmental dependence of u–r, u–g, g–r, r–i and i–z colors. All the five colors strongly correlate with the local environment: red galaxies tend to be located in dense regions, while blue galaxies tend to be located in low density regions. We also note that with increasing of redshift, the environmental dependence of galaxy colors becomes weaker, especially in the high redshift region (z between 0.17 and 0.20). This can be explained accepting that subsamples with high redshifts contain only luminous and red galaxies.

Using many-body dissipative particle dynamics (MDPD), polymer solutions with concentrations spanning dilute and semidilute regimes are modeled. The parameterization of MDPD interactions for systems with liquid–vapor coexistence is established by mapping to the mean-field Flory–Huggins theory. The characterization of static and dynamic properties of polymer chains is focused on the effects of hydrodynamic interactions and entanglements. The coil–globule transition of polymer chains in dilute solutions is probed by varying solvent quality and measuring the radius of gyration and end-to-end distance. Both static and dynamic scaling relations for polymer chains in poor, theta, and good solvents are in good agreement with the Zimm theory with hydrodynamic interactions considered. Semidilute solutions with polymer volume fractions up to 0.7 exhibit the screening of excluded volume interactions and subsequent shrinking of polymer coils. Furthermore, entanglements become dominant in the semidilute solutions, which inhibit diffusion and relaxation of chains. Quantitative analysis of topology violation confirms that entanglements are correctly captured in the MDPD simulations.

Abstract Background HLA-DRB1 allele polymorphisms have been reported to be associated with hepatocellular carcinoma susceptibility, but the results of these previous studies have been inconsistent. The purpose of the present study was to explore whether specific HLA-DRB1 alleles (DRB1*07, DRB1*12, DRB1*15) confer susceptibility to hepatocellular carcinoma. Methods Case-control studies on HLA-DRB1 alleles association with HCC were searched up to January 2010 through a systematic review of the literature. The odds ratios (ORs) of HLA-DRB1 allele distributions in patients with hepatocellular carcinoma were analyzed against healthy controls. The meta-analysis software REVMAN 5.0 was applied for investigating heterogeneity among individual studies and for summarizing all the studies. Meta-analysis was performed using fixed-effect or random-effect methods, depending on absence or presence of significant heterogeneity. Results Eight case-control studies were included in the final analysis. Among the 3 HLA-DRB1 alleles studied, DRB1*07 and DRB1*12 were significantly associated with the risk of HCC in the whole populations (OR = 1.65, 95% CI: 1.08-2.51, P = 0.02 and OR = 1.59, 95% CI: 1.09-2.32, P = 0.02, respectively). No significant association was established for DRB1*15 allele with HCC in the whole populations. Subgroup analysis by ethnicity showed that DRB1*07, DRB1*12 and DRB1*15 alleles significantly increased the risk of hepatocellular carcinoma in Asians (OR = 2.10, 95% CI: 1.06-4.14, P = 0.03; OR = 1.73, 95% CI: 1.17-2.57, P = 0.006 and OR = 2.88, 95%CI: 1.77-4.69, P <0.001, respectively). Conclusion These results support the hypothesis that specific HLA-DRB1 alleles might influence the susceptibility of hepatocellular carcinoma. Large, multi-ethnic confirmatory and well designed studies are needed to determine the host genetic determinants of hepatocellular carcinoma.