Entropy-controlled cross-linking in linker-mediated vitrimers.

Recently developed linker-mediated vitrimers based on metathesis of dioxaborolanes with various commercially available polymers have shown both good processability and outstanding performance, such as mechanical, thermal, and chemical resistance, suggesting new ways of processing cross-linked polymers in industry, of which the design principle remains unknown [M. Röttger et al., Science 356, 62-65 (2017)]. Here we formulate a theoretical framework to elucidate the phase behavior of the linker-mediated vitrimers, in which entropy plays a governing role. We find that, with increasing the linker concentration, vitrimers undergo a reentrant gel-sol transition, which explains a recent experiment [S. Wu, H. Yang, S. Huang, Q. Chen, Macromolecules 53, 1180-1190 (2020)]. More intriguingly, at the low temperature limit, the linker concentration still determines the cross-linking degree of the vitrimers, which originates from the competition between the conformational entropy of polymers and the translational entropy of linkers. Our theoretical predictions agree quantitatively with computer simulations, and offer guidelines in understanding and controlling the properties of this newly developed vitrimer system.

Duality, Hidden Symmetry, and Dynamic Isomerism in 2D Hinge Structures.

Recently, a new type of duality was reported in some deformable mechanical networks that exhibit Kramers-like degeneracy in phononic spectrum at the self-dual point. In this work, we clarify the origin of this duality and propose a design principle of 2D self-dual structures with arbitrary complexity. We find that this duality originates from the partial central inversion (PCI) symmetry of the hinge, which belongs to a more general end-fixed scaling transformation. This symmetry gives the structure an extra degree of freedom without modifying its dynamics. This results in dynamic isomers, i.e., dissimilar 2D mechanical structures, either periodic or aperiodic, having identical dynamic modes, based on which we demonstrate a new type of wave guide without reflection or loss. Moreover, the PCI symmetry allows us to design various 2D periodic isostatic networks with hinge duality. At last, by further studying a 2D nonmechanical magnonic system, we show that the duality and the associated hidden symmetry should exist in a broad range of Hamiltonian systems.

A case of acute pancreatitis induced by voriconazole during treatment of cryptococcal meningitis.

Acute pancreatitis refers to pancreatic enzyme activation caused by a variety of aetiologies, and mainly characterized by local inflammation of the pancreas, with or without diseases of other organ function changes. The main clinical features are abdominal pain and elevated trypsin levels in the blood. Common causes of acute pancreatitis include cholelithiasis, alcohol consumption and hyperlipidaemia, among which drugs are considered to be one of the rare causes of pancreatitis. The patient in this case was a 16-year-old adolescent female who developed acute severe pancreatitis during the treatment of cryptococcal meningitis with voriconazole for 35 days. Following diagnosis that pancreatitis was induced by voriconazole, the drug was immediately stopped and the patient was discharged after symptomatic treatment. The phenomenon of voriconazole-induced pancreatitis is extremely rare, but we hope that this report can arouse greater attention and vigilance of the majority of medical personnel to improve the safety of patients' medication, especially for children or minors.

Facilitated dynamics of an active polymer in 2D crowded environments with obstacles.

Understanding the behaviors of a single active chain in complex environments is not only an interesting topic in non-equilibrium physics but also has applicative implications in biological/medical engineering. In this work, by using molecular simulations, we systematically study the dynamical and conformational behaviors of an active polymer in crowded environments, i.e., a single active chain confined in 2D space with randomly arranged obstacles. We found that the competition between the chain's activity and rigidity in the presence of obstacles leads to many interesting dynamical and conformational states, such as the diffusive expanded state, the diffusive collapsed state, and the localized collapsed state. Importantly, we found a counter-intuitive phenomenon, i.e., crowded environments facilitate the diffusion of the active polymer within a large parameter space. As the crowdedness (packing fraction of obstacles) increases, the parameter space in which crowding-enhanced diffusion occurs still remains. This abnormal dynamics is attributed to a structural reason that the obstacles prevent active chains from collapsing. Our findings capture some generic features of active polymers in complex environments and provide insights into the design of novel drug delivery systems.

Alkynyl Borrowing: Silver-Catalyzed Amination of Secondary Propargylic Alcohols via C(sp3)-C(sp) Bond Cleavage.

The silver-catalyzed alkynyl borrowing amination of secondary propargyl alcohols via C(sp3)-C(sp) bond cleavage has been developed. This new strategy was based on the ß-alkynyl elimination of propargyl alcohols and alkynyl as the borrowing subject. This alkynyl borrowing amination featured high atom economy, wide functional group tolerance, and high efficiency.

A prospective epidemiological analysis of controlling nutritional status score with the poor functional outcomes in Chinese patients with haemorrhagic stroke.

Nutritional Risk Screening index is a standard tool to assess nutritional risk, but epidemiological data are scarce on controlling nutritional status (CONUT) as a prognostic marker in acute haemorrhagic stroke (AHS). We aimed to explore whether the CONUT may predict a 3-month functional outcome in AHS. In total, 349 Chinese patients with incident AHS were consecutively recruited, and their malnutrition risks were determined using a high CONUT score of ≥ 2. The cohort patients were divided into high-CONUT (≥ 2) and low-CONUT (< 2) groups, and primary outcomes were a poor functional prognosis defined as the modified Rankin Scale (mRS) score of ≥ 3 at post-discharge for 3 months. Odds ratios (OR) with 95 % confidence intervals (CI) for the poor functional prognosis at post-discharge were estimated by using a logistic analysis with additional adjustments for unbalanced variables between the high-CONUT and low-CONUT groups. A total of 328 patients (60·38 ± 12·83 years; 66·77 % male) completed the mRS assessment at post-discharge for 3 months, with 172 patients at malnutrition risk at admission and 104 patients with a poor prognosis. The levels of total cholesterol and total lymphocyte counts were significantly lower in high-CONUT patients than low-CONUT patients (P = 0·012 and < 0·001, respectively). At 3-month post discharge, there was a greater risk for the poor outcome in the high-CONUT compared with the low-CONUT patients at admission (OR: 2·32, 95 % CI: 1·28, 4·17). High-CONUT scores independently predict a 3-month poor prognosis in AHS, which helps to identify those who need additional nutritional managements.

Fasting blood glucose-to-glycated hemoglobin ratio and all-cause mortality among Chinese in-hospital patients with acute stroke: a 12-month follow-up study.

BACKGROUND: Stroke is a leading cause of death and functional impairment in older people. To assess the prospective association between fasting blood glucose-to-glycated hemoglobin ratio and all-cause mortality and poor prognosis in stroke patients. METHODS: A total of 971 Chinese inpatients with acute stroke (mean age of 65.7) were consecutively enrolled in the prospective clinical study and followed up for 12 months after discharge. Stress hyperglycemia was measured using the ratio of fasting blood glucose (FBG, mmol/L)/glycated hemoglobin (HbA1c, %). The primary outcome was all-cause mortality, and secondary outcomes were poor prognosis defined as infectious complications, a National Institutes of Health Stroke Scale (NIHSS) score ≥ 6, a Barthel Index score ≤ 60, or a modified Rankin Scale (mRS) score of 3-6, presented as multivariate-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) across the quartiles of the FBG/HbA1c ratio. RESULTS: There were 35 (4.1%) all-cause deaths at 3 months and 85 (11.4%) at 12 months. The inpatients with the highest quartile of the FBG/HbA1c ratio had a higher risk of all-cause death at 3 months (adjusted OR: 5.16, 95% CI: 1.03-25.74) and at 12 months (adjusted OR: 2.59, 95% CI: 1.14-5.89)) and a higher risk of infectious complications (adjusted OR 2.37, 95% CI 1.27-4.43) and dysfunction (adjusted OR 1.79, 95% CI 1.06-3.01) during hospitalization than inpatients with the lowest quartile. CONCLUSIONS: Stress hyperglycemia, measured by the FBG/HbA1c ratio, was associated with an increased risk of adverse outcomes, including all-cause death, infectious complications, and dysfunction after stroke.

Optimization of initial dose regimen of tacrolimus in paediatric lung transplant recipients based on Monte Carlo simulation.

WHAT IS KNOWN AND OBJECTIVES: The initial tacrolimus dose regimen in paediatric lung transplant recipients is unknown. The present study optimized the initial tacrolimus dose regimen for paediatric lung transplant recipients. METHODS: This study was based on a published population pharmacokinetic model of tacrolimus in lung transplant recipients and used Monte Carlo simulations to recommend an initial dose regimen of tacrolimus in paediatric lung transplant recipients. RESULTS: Without voriconazole, the tacrolimus doses recommended for paediatric lung transplant recipients who were not CYP3A5*1 carriers were 0.02, 0.03, and 0.04 mg/kg/day, split into two doses, for weights of 10-16, 16-30, and 30-40 kg, respectively. For paediatric lung transplant recipients who were CYP3A5*1 carriers, the tacrolimus doses of 0.03, 0.04, 0.05, and 0.06 mg/kg/day, split into two doses, were recommended for weights of 10-16, 16-25, 25-30, and 30-40 kg, respectively. With voriconazole, the tacrolimus dose recommended for paediatric lung transplant recipients who were not CYP3A5*1 carriers was 0.02 mg/kg/day, split into two doses, for weights of 10-40 kg. For paediatric lung transplant recipients who were CYP3A5*1 carriers, tacrolimus doses of 0.02 and 0.03 mg/kg/day, split and two doses, were recommended for weights of 10-24 and 24-40 kg, respectively. WHAT IS NEW AND CONCLUSIONS: This study developed tacrolimus dose regimens for the first time for paediatric lung transplant recipients using Monte Carlo simulation and optimized initial dosage in paediatric lung transplant recipients.

Hydrodynamics of random-organizing hyperuniform fluids.

Disordered hyperuniform structures are locally random while uniform like crystals at large length scales. Recently, an exotic hyperuniform fluid state was found in several nonequilibrium systems, while the underlying physics remains unknown. In this work, we propose a nonequilibrium (driven-dissipative) hard-sphere model and formulate a hydrodynamic theory based on Navier-Stokes equations to uncover the general mechanism of the fluidic hyperuniformity (HU). At a fixed density, this model system undergoes a smooth transition from an absorbing state to an active hyperuniform fluid and then, to the equilibrium fluid by changing the dissipation strength. We study the criticality of the absorbing-phase transition. We find that the origin of fluidic HU can be understood as the damping of a stochastic harmonic oscillator in q space, which indicates that the suppressed long-wavelength density fluctuation in the hyperuniform fluid can exhibit as either acoustic (resonance) mode or diffusive (overdamped) mode. Importantly, our theory reveals that the damping dissipation and active reciprocal interaction (driving) are the two ingredients for fluidic HU. Based on this principle, we further demonstrate how to realize the fluidic HU in an experimentally accessible active spinner system and discuss the possible realization in other systems.

Personal Guide Assisted Orthognathic Surgery: Application of a T-shaped Tooth Bone Combined Supporting Osteotomy Guide Plate and Positioning Guide Plate.

ABSTRACT: The precise movement of the maxilla is particularly important for orthognathic surgery, especially for patients with maxillary segmentation. In this preliminary study, the authors present a new tooth bone combined with a supporting osteotomy guide and positioning guide to guide the osteotomy and reduction of the maxilla. Through our preoperative simulation and postoperative image fusion, the authors found that the overlapping area is more than 90%. According to compare of the virtual plans and the postoperative results based on distances from the maxillary land- marks to the horizontal plane, sagittal plane, and coronal plane, the surgical error was about 2mm. Our T-shaped guide provides a reliable method for patients with maxillary segmental osteotomy, which may be a useful alternative to the intermediate.

Self-Assembly of Isostatic Self-Dual Colloidal Crystals.

Self-dual structures whose dual counterparts are themselves possess unique hidden symmetry, beyond the description of classical spatial symmetry groups. Here we propose a strategy based on a nematic monolayer of attractive half-cylindrical colloids to self-assemble these exotic structures. This system can be seen as a 2D system of semidisks. By using Monte Carlo simulations, we discover two isostatic self-dual crystals, i.e., an unreported crystal with pmg space-group symmetry and the twisted kagome crystal. For the pmg crystal approaching the critical point, we find the double degeneracy of the full phononic spectrum at the self-dual point and the merging of two tilted Weyl nodes into one critically tilted Dirac node. The latter is "accidentally" located on the high-symmetry line. The formation of this unconventional Dirac node is due to the emergence of the critical flatbands at the self-dual point, which are linear combinations of "finite-frequency" floppy modes. These modes can be understood as mechanically coupled self-dual rhombus chains vibrating in some unique uncoupled ways. Our work paves the way for designing and fabricating self-dual materials with exotic mechanical or phononic properties.

Supercrystallographic Reconstruction of 3D Nanorod Assembly with Collectively Anisotropic Upconversion Fluorescence.

Constructing three-dimensional (3D) metamaterials from functional nanoparticles endows them with emerging collective properties tailored by the packing geometries. Herein, we report 3D supercrystals self-assembled from upconversion nanorods (NaYF4:Yb,Er NRs), which exhibit both translational ordering of NRs and orientational ordering between constituent NRs in the superlattice (SL). The construction of 3D reciprocal space mappings (RSMs) based on synchrotron-based X-ray scattering measurements was developed to uncover the complex structure of such an assembly. That is, the two main orthogonal sets of hexagonal close-packing (hcp)-like SLs share the [110]SL axis, and NRs within the SL possess orientational relationships of [120]NR//[100]SL, [210]NR//[010]SL, and [001]NR//[001]SL. Notably, these supercrystals containing well-aligned NRs exhibit collectively anisotropic upconversion fluorescence in two perpendicular directions. This study not only demonstrates novel crystalline superstructures and functionality of NR-based 3D assemblies but also offers a unique tool for deciphering a wide range of complex nanoparticle supercrystals.

[Progress of studies on anti-breast tumor mechanism of alkaloids].

Breast tumor has become one of the malignant tumors with the highest incidence, and is a serious threat to human health, especially to women. Chemotherapy is an important anti-breast tumor therapy, which can be used in almost every stage of breast tumor therapy alone or in the combination with surgery and radiation therapy. Alkaloids are a kind of ubiquitous natural products, and important active components of various medicinal plants. A large number of studies have shown that alkaloids could exert an anti-breast tumor effect by inhibiting proliferation, metastasis and angiogenesis, resisting mitosis, promoting apoptosis and autophagy, and triggering cell cycle arrest. The extensive anti-breast tumor effect makes alkaloids an important candidate drug source. This paper reviews the anti-breast tumor mechanism of natural products of alkaloids.

Hierarchical glass transition of hard hemidisks with local assemblies.

Using computer simulation, we investigate the glass transition of a two-dimensional hard-hemidisk system. Upon increasing the packing fraction of the system, we find that the system vitrifies into a glass with local assembled discal "dimers", which are free to rotate in a collective way. The rotational mean square displacement does not exhibit the typical plateau (slowdown) like what occurs in the translational mean square displacement. This effect induces a pronounced violation of the rotational Stokes-Einstein relationship compared with the translational degree of freedom at the supercooled region. However, the obtained glass transition points in these two freedom degrees are found to be the same within the numerical accuracy, which is due to the strong positive spatial and dynamic correlation between translational and rotational slow-moving particles. Moreover, we find that the locally assembled dimers can serve as fast rotating gears facilitating the orientational relaxation in the system, and this suggests that the locally favored finite structures play an important role in the hierarchical glass transition of anisotropic colloids.

One-Pot Synthesis of 2,4-Diacyl Thiophenes from α-Oxo Ketene Dithioacetals and Propargylic Alcohols.

Although thiophenes having various functionalities are the basic structural units in numerous bioactive compounds and optoelectronic materials, synthetic routes to acylated thiophenes from aliphatic sulfur-containing starting materials are still rare. In particular, there have been no reports concerning the straightforward synthesis of 2,4-diacylthiophenes from alkynes. Herein, we describe a highly efficient and metal-free three-step one-pot synthetic approach to tetrasubstituted 2,4-diacylthiophenes from propargylic alcohols and α-oxo ketene dithioacetals. This research features a relay catalysis system that integrates Brønsted acid-catalyzed propargylation, molecular iodine-mediated electrophilic cyclization, and visible light-induced deiodinative oxygenation. The 2,4-diacylthiophenes serving as the key starting materials are readily synthesized, enabling facile construction of analogues of related biologically active compounds and the modular assembly of tetrasubstituted thienothiophenes.

Self-assembled multi-layer simple cubic photonic crystals of oppositely charged colloids in confinement.

Designing and fabricating self-assembled open colloidal crystals have become one major direction in the soft matter community because of many promising applications associated with open colloidal crystals. However, most of the self-assembled crystals found in experiments are not open but close-packed. Here, by using computer simulation, we systematically investigate the self-assembly of oppositely charged colloidal hard spheres confined between two parallel hard walls, and we find that the confinement can stabilize multi-layer NaCl-like (simple cubic) open crystals. The maximal number of layers of stable NaCl-like crystals increases with decreasing inverse screening length. More interestingly, at finite low temperature, the large vibrational entropy can stabilize some multi-layer NaCl-like crystals against the most energetically favoured close-packed crystals. In the parameter range studied, we find up to 4-layer NaCl-like crystals to be stable in confinement. Our photonic calculation shows that the inverse 4-layer NaCl-like crystal can already reproduce the large photonic band gaps of the bulk simple cubic crystal, which open in the low frequency range with a low dielectric contrast. This suggests new possibilities of using confined colloidal systems to fabricate open crystalline materials with novel photonic properties.

Humanistic Spirit Contained in Traditional Chinese Medicine should Be Valued.

Medicine is a science studying human's health and diseases as well as the regularity between them. Its research subject is human, who possess natural attribute, psychological attribute and social attribute. Therefore, medicine is bound to possess humanistic attribute. Rooted in Chinese traditional culture, Traditional Chinese Medicine contains abundant humanistic thoughts, for instance, pursuing the unity of human and nature, advocating the vital importance of life, sticking to the virtue of "medicine being humane art", abiding by the principle of "Benevolence prior to interest", complying with the medical rule of "Respecting peers". These are the very concrete reflections of medical humanistic spirit. In this article we aim to explore the humanistic thoughts contained in Traditional Chinese Medicine, and try to inherit and carry forward the spirit to better relieve the tensions between doctors and patients and improve the quality of medical services.

[Clinicopathologic features of testicular seminoma with syncytiotrophoblastic cells: Analysis of 3 cases and review of the literature].

OBJECTIVE: To investigate the clinical and histopathologic features of testicular seminoma with syncytoplasmic trophoblastic components. METHODS: Using light microscopic staining, we analyzed the clinical and histopathologic characteristics, diagnosis, differential diagnosis and prognosis of 3 cases of testicular seminoma with syncytoplasmic trophoblastic components, and reviewed the relevant literature. RESULTS: All the 3 cases were typical seminoma with syncytiotrophoblastic giant cells. Immunohistochemistry showed strong expressions of CD117 OCT-4, SALL4 and PLAP in diffuse tumor cells, and that of hCG in syncytiotrophoblastic cells. Continuous monitoring and consultation exhibited normal levels of serum ß-hCG in all the cases after postoperative chemotherapy. CONCLUSIONS: Testicular seminoma with syncytiotrophoblastic giant cells and increased serum ß-hCG is a rare subtype, which occurs mostly in young people, sensitive to chemotherapy postoperatively and with a relatively good prognosis.

[Clinicopathological characterization of non-Hodgkin lymphoma of the prostate].

OBJECTIVE: To study the clinicopathological characteristics of non-Hodgkin lymphoma (NHL) of the prostate. METHODS: We collected the clinical data on 6 cases of NHL of the prostate pathologically confirmed between 2001 and 2017. The patients were aged 49－76 (median 62) years old, with the main clinical manifestations of painless swelling of the prostate and lower urinary tract obstruction. We analyzed the clinical features and the results of histological detection, immunohistochemical staining and B-cell gene rearrangement assay, and explored the clinicopathological characteristics and differential diagnosis of the disease based on the relevant literature. RESULTS: Histological detection revealed diffuse large B-cell lymphoma (DLBCL) in 4 cases (66.7%), B-lymphoblastic lymphoma (B-LBL) in 1 (16.7%), and Burkitt lymphoma (BL) in another (16.7%). DLBCL was histologically characterized by diffuse oval or round medium-to-large-sized lyphoid cells with an infiltrative growth pattern, B-LBL by monotonous small-to-medium-sized lymphoid cells with prominet mitosis and apoptosis, and BL by diffuse and monotonous medium-sized neoplastic cells with round or oval nuclei, an infiltrative growth pattern, scanty cytoplasm and visible mitosis. One of the DLBCL patients received 5 doses of R-CHOP chemotherapy and has been followed up to the present time, while the other 3 were lost to follow-up; the B-LBL patient died at 1 month after diagnosis; and the BL patient gave up treatment. CONCLUSIONS: Non-Hodgkin's lymphoma of the prostate mostly presents as diffuse large B-cell lymphoma, and its diagnosis depends on immunohistochemistry and related molecular detection as well as its clinical and histopathological manifestations.

[Primary testicular diffuse large B-cell lymphoma: A clinicopathological analysis].

OBJECTIVE: To investigate the clinicopathological features, immunophenotype and treatment of primary testicular diffuse large B-cell lymphoma (DLBCL). METHODS: We retrospectively analyzed the pathomorphological characteristics and immunohistochemical markers of 23 cases of primary testicular DLBCL as well as their clinicopathological features with a review of the relevant literature. The patients were aged 48－76 (mean 61.4) years, 82.6% over 50 years, and all clinically presented with painless progressive unilateral testicular swelling, 9 cases in the left and the other 14 in the right testis. RESULTS: Histologically, the lymphomas were composed of large atypical cells with prominent karyokinesis and diffusely infiltrated the testicular parenchyma. The neoplastic cells were positive for B-cell markers. Five of the patients were followed up for 2 to 32 months, of whom 4 survived and 1 died at 9 months. CONCLUSIONS: Primary testicular DLBCL is a rare tumor with an invasive biological behavior, mostly found in elderly males and easily misdiagnosed or missed in diagnosis. Histopathology plays a key role and immunohistochemical markers are of high value in the definite diagnosis and differential diagnosis of the tumor.