Efficacy and safety of antiplatelet therapy in COVID-19: Insights from a meta-analysis of randomized controlled trials.

BACKGROUND: COVID-19 induces a pro-coagulant state with thrombotic events. This meta-analysis explores the efficacy and safety of antiplatelet-based therapy in COVID-19 patients through randomized controlled trials (RCTs). MATERIALS AND METHODS: A systematic literature search until March 10, 2023, identified 7 RCTs involving 23,415 inpatients. Of these, 11,891 received antiplatelet-based treatment, and 11,524 received placebo/other drugs. Statistical analysis was performed using Review Manager 5.4. RESULTS: The included trials involved patients with a mean age ranging from 54.3 to 62.0 years and a prevalence of hypertension ranging from 10.9 to 65.0% and coronary artery disease ranging from 3.2 to 32.7%. The pooled analysis showed no significant difference in overall mortality between groups (RR 1.0, 95% CI 0.99 - 1.01, p = 0.76). However, antiplatelet therapy significantly reduced major thrombotic events (RR 0.86, 95% CI 0.75 - 0.99, p = 0.04). Conversely, it increased major bleeding risks (RR 1.62, 95% CI 1.24 - 2.12, p = 0.0005). There was no significant difference in the incidence of invasive mechanical ventilation and respiratory death. CONCLUSION: Antiplatelet therapy does not confer mortality benefit in COVID-19 patients but lowers major thrombotic events while increasing major bleeding risks. Ongoing large RCTs will provide more information on the therapeutic value of this therapy.

High-flux wavelength tunable XUV source in the 12-40.8†eV photon energy range with adjustable energy and time resolution for Tr-ARPES applications.

High-order harmonic generation (HHG) has a broad spectrum covering vacuum ultraviolet to extreme ultraviolet (XUV) bands, which is useful for applications involving material analyses at different information depths. Such an HHG light source is perfect for time- and angle-resolved photoemission spectroscopy. Here, we demonstrate a high-photon flux HHG source driven by a two-color field. Applying a fused silica compression stage to reduce the driving pulse width, we obtained a high XUV photon flux of 2 × 1012 phs/s @21.6 eV on target. We designed a classical diffraction mounted (CDM) grating monochromator that can achieve a wide range of photon energy from 12 to 40.8 eV, while the time resolution is improved by reducing the pulse front tilt after the harmonic selection. We designed a spatial filtering method to adjust the time resolution using the CDM monochromator and significantly reduced the pulse front tilt of the XUV pulses. We also demonstrate a detailed prediction of the energy resolution broadening which is caused by the space charge effect.

A meta-analysis of randomized controlled trials of statin-based therapy in patients with COVID-19.

BACKGROUND: Previous observational studies and meta-analyses have suggested that statins could be beneficial in reducing the risk of adverse clinical outcomes. This study is the first to conduct a meta-analysis of recently published randomized controlled clinical trials investigating the potential therapeutic benefits of statins for COVID-19. MATERIALS AND METHODS: A thorough search was conducted using databases such as PubMed and Embase until May 2023 to identify randomized controlled clinical trials investigating the use of statins in patients with COVID-19. Review Manager 5.4 was used to analyze the selected studies. RESULTS: Seven randomized controlled trials comprising a total of 2,370 patients were included in this study. Of these, 1,295 patients received statin therapy, while 1,075 received placebo or other drugs. All included studies were conducted on inpatients with an average age of 45 - 61 years, and the proportion of patients with diabetes and coronary heart disease was less than 30%. One study only included severely ill patients. Our results showed that statin treatment did not significantly reduce hospitalized patient mortality (11.5 vs. 13.4%, p = 0.94), the proportion of patients transferred to intensive care due to disease changes (14.2 vs. 11.2%, p = 0.41), or the proportion of patients requiring mechanical ventilation (5.3 vs. 7.9%, p = 0.71) compared to controls. However, the use of statins was associated with a slight increase in hospital stay. CONCLUSION: A critical appraisal of published randomized controlled trials on statin therapy in COVID-19 did not show any significant effect on mortality, the risk of transfer to intensive care, or mechanical ventilation.

Effect of preoperative contralateral foramen stenosis on contralateral root symptoms after unilateral transforaminal lumbar interbody fusion: a ambispective cohort study.

PURPOSE: To evaluate the correlation between the degree of preoperative contralateral foraminal stenosis(CFS) and the incidence of contralateral root symptoms after unilateral transforaminal lumbar interbody fusion(TLIF) and to evaluate the appropriate candidate of preventive decompression according to the degree of preoperative contralateral foraminal stenosis. METHODS: An ambispective cohort study was conducted to investigate the incidence of contralateral root symptoms after unilateral transforaminal lumbar interbody fusion (TLIF) and the effectiveness of preventive decompression. A total of 411 patients were included in the study, all of whom met the inclusion and exclusion criteria and underwent surgery at the Department of Spinal Surgery, Ningbo Sixth Hospital, between January 2017 and February 2021. The study was divided into two groups: retrospective cohort study A and prospective cohort study B. The 187 patients included in study A from January 2017 to January 2019 did not receive preventive decompression. They were divided into four groups based on the degree of preoperative contralateral intervertebral foramen stenosis: no stenosis group A1, mild stenosis group A2, moderate stenosis group A3, and severe stenosis group A4. A Spearman rank correlation analysis was used to evaluate the correlation between the preoperative contralateral foramen stenosis degree and the incidence of contralateral root symptoms after unilateral TLIF. From February 2019 to February 2021, 224 patients were included in the prospective cohort group B. The decision to perform preventive decompression during the operation was based on the degree of preoperative contralateral foramen stenosis. Severe intervertebral foramen stenosis was treated with preventive decompression as group B1, while the rest were not treated with preventive decompression as group B2. The baseline data, surgical-related indicators, the incidence of contralateral root symptoms, clinical efficacy, imaging results, and other complications were compared between group A4 and group B1. RESULTS: All 411 patients completed the operation and were followed up for an average of 13.5 ± 2.8 months. In the retrospective study, there was no significant difference in baseline data among the four groups (P > 0.05). The incidence of postoperative contralateral root symptoms increased gradually, and a weak positive correlation was found between the degree of preoperative intervertebral foramen stenosis and the incidence of postoperative root symptoms (rs = 0.304, P < 0.001). In the prospective study, there was no significant difference in baseline data between the two groups. The operation time and blood loss in group A4 were less than those in group B1 (P < 0.05). The incidence of contralateral root symptoms in group A4 was higher than that in group B1 (P = 0.003). However, there was no significant difference in leg VAS score and ODI index between the two groups at 3 months after the operation (P > 0.05). There was no significant difference in cage position, intervertebral fusion rate, and lumbar stability between the two groups (P > 0.05). No incisional infection occurred after the operation. No pedicle screw loosening, displacement, fracture, or interbody fusion cage displacement occurred during follow-up. CONCLUSION: This study found a weak positive correlation between the degree of preoperative contralateral foramen stenosis and the incidence of contralateral root symptoms after unilateral TLIF. Intraoperative preventive decompression of the contralateral side may prolong the operation time and increase intraoperative blood loss to some extent. However, when the contralateral intervertebral foramen stenosis reaches the severe level, it is recommended to perform preventive decompression during the operation. This approach can reduce the incidence of postoperative contralateral root symptoms while ensuring clinical efficacy.

Analysis of risk factors for contralateral symptomatic foraminal stenosis after unilateral transforaminal lumbar interbody fusion.

PURPOSE: To analyze the risk factors of contralateral symptomatic foraminal stenosis (FS) after unilateral transforaminal lumbar interbody fusion (TLIF) and to guide and standardize the operation process of unilateral TLIF to reduce the occurrence of contralateral symptomatic FS. METHODS: A retrospective study was undertaken on 487 patients with lumbar degeneration who underwent unilateral TLIF in the Department of Spinal Surgery of Ningbo Sixth Hospital between January 2017 and January 2021, comprising 269 males and 218 females, with a mean age of 57.1 years (range, 48-77 years). Cases of intraoperative improper operations, such as screw deviation, postoperative hematoma, and contralateral disc herniation, were excluded, and cases of nerve root symptoms caused by contralateral FS were analyzed. Post-surgery, 23 patients with nerve root symptoms caused by contralateral FS were categorized as group A, and 60 patients without nerve root symptoms were randomly selected as group B during the same period. The general data (gender, age, body mass index (BMI), bone mineral density (BMD), and diagnosis) and imaging parameters before and after operation (including contralateral foramen area (CFA), lumbar lordosis angle (LL), segmental lordosis angle (SL), disc height (DH), foramen height (FH), foramen width (FW), fusion cage position, and the difference between postoperative and preoperative) were compared between the two groups. Univariate analysis was performed, and multivariate analysis was undertaken through logistics analysis to determine the independent risk factors. Additionally, the clinical outcomes of the two groups were compared immediately before surgery and one year after surgery, using the visual analogue scale (VAS) score and the Japanese Orthopaedic Association (JOA) score for evaluation. RESULTS: The patients in this study were followed up for a period of 19-25 (22.8atien months. Among them, 23 cases (4.72% incidence) were diagnosed with contralaterally symptomatic FS after the surgery. Univariate analysis indicated significant differences between the two groups in CFA, SL, FW, and cage coronal position. Logistic regression analysis identified preoperative contralateral foramen area (OR = 1.176, 95% CI (1.012, 1.367)), small segmental lordosis angle (OR = 2.225, 95% CI (1.124, 4.406)), small intervertebral foramen width (OR = 2.706, 95% CI (1.028, 7.118)), and cage coronal position not crossing the midline (OR = 1.567, 95% CI (1.142, 2.149)) as independent risk factors for contralateral symptomatic FS after unilateral TLIF. However, there was no statistically significant difference in the pain VAS score between the two groups one year after the operation. In contrast, there was a significant difference in the JOA score between the two groups. CONCLUSION: The identified risk factors for contralateral symptomatic FS after TLIF include preoperative contralateral intervertebral foramen stenosis, a small segmental lordosis angle, a small intervertebral foramen width, and the coronal position of the cage not crossing the midline. For patients with these risk factors, it is recommended to carefully lock the screw rod during the recovery of lumbar lordosis and ensure that the coronal position of the fusion cage is implanted beyond the midline. If necessary, preventive decompression should also be considered. However, this study did not quantify the imaging data for each risk factor, and further research is needed to improve our understanding of the topic.

Rapid and sensitive detection of Hg2+ with a SERS-enhanced lateral flow strip.

Mercury ions are some of the most toxic heavy metal ions widely distributed in the environment. Hg2+ cannot be degraded by microorganisms and can accumulate in the body through the food chain, posing a great threat to human health. Herein, a method combining surface-enhanced Raman scattering (SERS) with a lateral flow strip (LFS) (SERS-LFS) was developed for the rapid and quantitative analysis of Hg2+. The recognition of Hg2+ by the LFS depends on a specific T-Hg-T strategy. Rhodamine 6G (R6G), as a SERS reporter, was assembled on the surface of Au@Ag core-shell nanoparticles, which served as an effective SERS substrate on both the T and C lines of the LFS. Using this SERS-LFS, the presence of target Hg2+ could be measured through the appearance of an orange color on the T line of the LFS. Furthermore, with the direct measurement of SERS on the T lines of the LFS, the SERS signal could be collected even at a low concentration of Hg2+, at which point the signal on the T lines could not be observed. Based on the intensities of the characteristic peak at 1513 cm-1 of R6G collected on the T lines of the LFS, a linear relationship was obtained in the range of 0.01 nM to 1 nM, and the detection limit of the LFS was greatly improved by at least 20 times over the colorimetric results of the traditional LFS based on naked-eye observation. More importantly, this SERS-LFS did not affect the intrinsic simplicity of the LFS. This developed SERS-LFS holds great potential in practical routine screening in food safety and environmental monitoring.

A nomogram based on CHADS2 score for predicting atrial fibrillation recurrence after cryoballoon ablation.

BACKGROUND: As reported, CHADS2 scoring system moderately predicts the atrial fibrillation (AF) recurrence, a common event after cryoballoon ablation. We aimed to improve the diagnostic accuracy of the CHADS2 score by adding several routine auxiliary detection indicators into the scoring system and constructing a CHADS2 score-based nomogram to predict AF recurrence in patients with paroxysmal AF undergoing cryoballoon ablation. METHODS: Eighty-four patients with paroxysmal AF undergoing cryoballoon ablation were enrolled. Baseline characteristics were collected. The multivariable Cox proportional hazards model was used to identify the significantly related predictors of recurrence and to construct the nomogram whose performance was evaluated by the discrimination and calibration tests. RESULTS: Thirty-five patients developed AF recurrence after a mean follow up of 19.0 ± 15.77 months. In the Cox multivariate model, CHADS2 (>2) (hazard ratio [HR]: 2.38; 95% confidence interval [CI]: 1.14-4.98, p = .021) and albumin-to-globulin ratio (AGR) (HR: 2.49; 95% CI: 1.26-4.92, p < .008) were independent risk factors associated with AF recurrence. In addition to CHADS2 , AGR and red blood cell distribution width were used to construct the nomogram. As a result, the discrimination of the concordance index for the predictive model of AF recurrence was increased from 0.56 (95% CI: 0.494-0.632) to 0.712 (95% CI: 0.631-0.811). The 24-month one well matched the ideal 45° line among the calibration plots for 6, 12, and 24 months' recurrence-free survival. CONCLUSION: This novel easy-to-use CHADS2 score-based nomogram may be used to predict AF recurrence for patient of paroxysmal AF undergoing cryoballoon ablation. Further external validation is still needed.

High performance benzene vapor sensor based on three-dimensional photonic crystals of zeolitic imidazolate framework-8@graphene quantum dots.

Superior sensitive, selective, and repeatable real-time detection of low concentrations of benzene vapor is vitally important for environmental protection and human health. A benzene vapor sensor using three-dimensional photonic crystals (3-D PCs) based on zeolitic imidazolate framework-8@graphene quantum dots (ZIF-8@GQDs) was proposed. The 3-D PCs were acquired by centrifuging ZIF-8@GQDs pseudo-solutions, which were prepared via hydrothermal methods. The application of the ZIF-8@GQDs 3-D PCs sensor for optical benzene vapor detection via the strong π-π stacking interactions and large specific surface area and abundant open-framework structure of the ZIF-8@GQDs was investigated. The ZIF-8@GQDs 3-D PCs sensor exhibits a more sensitive response to benzene vapor compared with the ZIF-8 3-D PCs sensor. The relationship between the wavelength shift and the benzene vapor concentration was demonstrated to be linear. Additionally, the ZIF-8@GQDs 3-D PCs sensor presents a fast optical response and recovery times of 1 s and 7 s for 200 ppm benzene vapor detection, the benzene vapor detection limit can reach 1 ppm, and the deviation of the reflected wavelength varied within 2 nm after 10 cycles. Moreover, the fabricated ZIF-8@GQDs 3-D PCs sensor exhibited reliability and exceptional thermal and long-time storage stability, demonstrating great potential for practical benzene vapor sensing applications.

Cadaveric biomechanical analysis of multilevel lateral lumbar interbody fusion with and without supplemental instrumentation.

BACKGROUND: This study was to evaluate and compare the biomechanical features of multilevel lateral lumbar interbody fusion (LLIF) with or without supplemental instrumentations. METHODS: Six human lumbar specimens were tested under multidirectional nondestructive moments (7.5 N·m), with a 6 degree-of-freedom spine simulator. The overall and intervertebral range of motion (ROM) were measured optoelectronically. Each specimen was tested under the following conditions at L2-5 levels: intact; stand-alone; cage supplemented with lateral plate (LP); cage supplemented with unilateral or bilateral pedicle screw/rod (UPS or BPS). RESULTS: Compared with intact condition, the overall and intersegmental ROM were significantly reduced after multilevel stand-alone LLIF. The ROM was further reduced after using LP instrumentation. In flexion-extension (FE) and axial rotation (AR), pedicle screw/rod demonstrated greater overall ROM reduction compared to LP (P < 0.01), and bilateral greater than unilateral (P < 0.01). In lateral bending (LB), BPS demonstrated greater overall ROM reduction compared to UPS and LP (P < 0.01), however, UPS and LP showed similar reduction (P = 0.245). Intervertebral ROM reductions showed similar trend as the overall ones after using different types of instrumentation. However, at L2/3 (P = 0.57) and L3/4 (P = 0.097) levels, the intervertebral ROM reductions in AR were similar between UPS and LP. CONCLUSIONS: The overall and intervertebral stability increased significantly after multilevel LLIF with or without supplemental instrumentation. BPS provided the greatest stability, followed by UPS and LP. However, in clinical practice, less invasive adjunctive fixation methods including UPS and LP may provide sufficient biomechanical stability for multilevel LLIF.

Unique mechanistic insights into the beneficial effects of angiotensin-(1-7) on the prevention of cardiac fibrosis: A metabolomic analysis of primary cardiac fibroblasts.

BACKGROUND: Cell metabolic pathways are highly conserved among species and change rapidly in response to drug stimulation. Therefore, we explore the effects of angiotensin-(1-7) in a primary cell model of cardiac fibrosis established in angiotensin II-stimulated cardiac fibroblasts via metabolomics analysis and further clarify the potential protective mechanism of angiotensin-(1-7). METHODS AND RESULTS: After exposing cardiac fibroblasts to angiotensin II and/or angiotensin-(1-7), 172 metabolites in these cells were quantified and identified by gas chromatography-mass spectrometry. The data were subsequently analyzed by orthogonal partial least squares discriminant analysis to shortlist biochemically significant metabolites associated with the antifibrotic action of angiotensin-(1-7). Seven significant metabolites were identified: 10,13-dimethyltetradecanoic acid, arachidonic acid, aspartic acid, docosahexaenoic acid (DHA), glutathione, palmitelaidic acid, and pyroglutamic acid. By metabolic network analysis, we found that these metabolites were involved in six metabolic pathways, including arachidonic acid metabolism, leukotriene metabolism, and the γ-glutamyl cycle. Since these metabolic pathways are related to calcium balance and oxidative stress, we further verified that angiotensin-(1-7) suppressed the abnormal extracellular calcium influx and excessive accumulation of intracellular reactive oxygen species (ROS) in angiotensin II-stimulated cardiac fibroblasts. Furthermore, we found that angiotensin-(1-7) suppressed the abnormal calcium- and ROS-dependent activation of calcium/calmodulin-dependent protein kinase II delta (CaMKIIδ), the increased expression of CaMKIIδ-related proteins (NADPH oxidase 4 (Nox4), cellular communication network factor 2 (CTGF), and p-ERK1/2), and excessive collagen deposition in vitro and in vivo. CONCLUSIONS: Angiotensin-(1-7) can ameliorate the angiotensin II-stimulated metabolic perturbations associated with cardiac fibroblast activation. These metabolic changes indicate that modulation of calcium- and ROS-dependent activation of CaMKIIδ mediates the activity of angiotensin-(1-7) against cardiac fibrosis. Moreover, pyroglutamic acid and arachidonic acid may be potential biomarkers for monitoring the antifibrotic action of angiotensin-(1-7).

Missed manubriosternal dislocation in patient with thoracolumbar fracture, a case report.

BACKGROUND: Spine fractures combined with sternal injury are most commonly occur in the thoracic region. Lower cervical and thoracolumbar injuries have also been reported, especially for the patients with manubriosternal dislocation. The type of spine injury is easily recognized in initial presentation, but we may miss the sternal fracture and manubriosternal dislocation. CASE PRESENTATION: A 23-year-old male patient complained with chest, right ankle, and lumbar pain after a fall at ground level, with diagnosis of right distal tibial fracture, sternal fracture, calcaneus fracture, and L2 vertebral fracture. However, neurologically he was completely normal. He underwent the operation for his lower extremity and spine, but we missed his manubriosternal dislocation after discharged. After one month, he came to the clinic with complained of chest pain, the imaging exams showed anterior dislocation of manubriosternal joint. We chose conservative treatment for manubriosternal dislocation. He was followed up at monthly intervals and radiographs along with computerized tomography showed satisfactory in fracture healing of lumber and the sternal fracture. However, the manubriosternal dislocation was malunioned. The patient had appearance deformity of the manubriosternal joint. CONCLUSION: This case supports the concept of the existence and clinical relevance of the thoracic cage theory, the thoracolumbar vertebrae should also be included in the thoracic cage theory.

Angiotensin II upregulates fibroblast-myofibroblast transition through Cx43-dependent CaMKII and TGF-ß1 signaling in neonatal rat cardiac fibroblasts.

In cardiac fibroblasts, angiotensin II (Ang II) can increase connexin 43 (Cx43) expression and promote calmodulin-dependent protein kinase II (CaMKII) activation. Cx43 overexpression is crucial for the fibroblast-myofibroblast transition. The main purpose of the present study was to investigate the role of CaMKII in regulating Cx43 expression and to determine whether the CaMKII/Cx43 pathway is essential for controlling fibroblast activation and differentiation. In vivo, 4 weeks of Ang II infusion enhanced CaMKII activation but reduced Cx43 expression in hearts undergoing fibrosis remodeling, while in cultured neonatal rat fibroblasts, CaMKII activation upregulated Cx43 expression via transforming growth factor-beta1 (TGF-ß1). CaMKII inhibition by Ang-(1-7) or autocamtide 2-related inhibitory peptide reversed the Ang II-induced changes in Cx43 expression and attenuated Ang II-induced upregulation of alpha smooth muscle actin and TGF-ß1 in both Ang II-infused rats and cultured fibroblasts. Based on the in vivo and in vitro experimental results, CaMKII plays a pivotal role in the Ang II-mediated fibroblast-myofibroblast transition by modulating the expressions of TGF-ß1 and Cx43. We conclude that Ang II mediates the fibroblast-myofibroblast transition partially via the Ang II/CaMKII/TGF-ß1/Cx43 signaling pathway.

Surgical treatment of compressive spinal hemangioma : A case series of three patients and literature review.

PURPOSE: In this article we describe the treatment of compressive vertebral hemangioma. METHODS: Our case series comprised three patients with aggressive hemangioma. We performed a combination of posterior decompression and vertebroplasty for the two patients with a sacral hemangioma and a thoracic hemangioma, and en bloc resection for the third patient, who also had a thoracic lesion. RESULTS: Surgical intervention is indicated in cases of rapidly progressive tumors or severe myelopathy. All three patients had good clinical results. The follow-up period ranged from 8 to 56 months. The mean blood loss was around 700 ml, and mean surgical time was 2.1 h. Blood loss for the en bloc procedure was around 1,200 ml, and surgical time was 2.3 h. CONCLUSION: A combination of posterior decompression, vertebroplasty, and posterior fixation for aggressive hemangioma can reduce blood loss during surgery. For patients with hemangioma and with incomplete paralysis, total en bloc spondylectomy should be considered. Adjuvant radiotherapy can reduce the recurrence of cavernous vertebral hemangiomas.

Clinical outcomes of transtibial versus anteromedial drilling techniques to prepare the femoral tunnel during anterior cruciate ligament reconstruction.

PURPOSE: The clinical outcomes of transtibial (TT) and anteromedial (AM) drilling techniques for anterior cruciate ligament reconstruction in preparing the femoral tunnel were directly compared by using a systematic literature review. METHODS: PubMed, EMBASE, the Cochrane Library, and the ISI Web of Science were searched until 10 May 2014, using the following Boolean operators: transtibial AND (anteromedial OR transportal OR independent OR three portal OR accessory portal) AND anterior cruciate ligament. All prospective and retrospective controlled trials directly comparing physical examination and scoring system results between TT and AM techniques were retrieved. No language or publication year limitations were used in our analysis. RESULTS: Of 504 studies retrieved, nine studies involving 769 patients were included. Results suggested that the AM was superior to the TT technique for preparing the femoral tunnel independent of the International Knee Documentation Committee (IKDC) Score (n.s.). A higher proportion of negative Lachman (p = 0.002) and pivot-shift test (p = 0.01) results, lower manual maximum displacement by KT-1000 (p = 0.004), higher Lysholm scores (p = 0.034), a higher incidence of IKDC grade A/B (p = 0.04), and higher visual analogue scale scores (p = 0.00) were observed with the AM compared with the TT technique. CONCLUSION: Although the increases in these scores were below the minimal clinically important difference, this systematic review indicated that the AM was superior to the TT drilling technique based on physical examination and scoring system results. LEVEL OF EVIDENCE: Therapeutic study (systematic review), Level III.

Cementless Porous Tantalum Monoblock Tibia vs Cemented Modular Tibia in Primary Total Knee Arthroplasty: A Meta-Analysis.

BACKGROUND: With the introduction of new fixation systems and designs, there has been a recent reemergence of interest in cementless fixation of the tibial component in total knee arthroplasty. However, little is known regarding the clinical features and survivorship of the cementless porous tantalum monoblock tibial component compared to the conventional cemented modular tibial component. METHODS: We conducted a literature search of multiple databases for comparative studies published before June 2015 that investigated the outcomes of cementless porous tantalum monoblock tibia vs conventional cemented modular tibia. A pooled analysis was performed. The outcomes of interest were postoperative functional score, range of motion, Western Ontario and McMaster University Osteoarthritis Index, total complications, reoperation, radiolucent lines, loosening of the tibial component, and length of operation. RESULTS: Six studies involving 977 patients were eligible for the meta-analysis. The use of a cementless porous tantalum monoblock tibial component may associate with a slightly higher functional score, fewer radiolucent lines, and shorter operation. No significant difference was seen in regard to the range of motion, Western Ontario and McMaster University Osteoarthritis Index, total complications, reoperation, and loosening of the component between the 2 groups. CONCLUSION: However, due to variation among the included studies, the use of cementless porous tantalum monoblock tibia seems to achieve no substantial superiority over that of the conventional cemented modular tibia at 5-year follow-up. Data concerning the long-term prognosis of this novel implant should continue to be collected and analyzed.

The structure factor of a wormlike chain and the random-phase-approximation solution for the spinodal line of a diblock copolymer melt.

An efficient and convenient numerical approach to calculate the structure factor of a wormlike chain model is proposed by directly dealing with a formal solution of the Green's function. A precise numerical representation of the structure factor of the wormlike chain model is then obtained, for arbitrary chain rigidity. On one hand, in the flexible limit, the numerical results recover the well-known Debye function of the structure factor of a Gaussian chain and furthermore predict the correct large-k behavior that a Gaussian model fails to capture; on the other hand, in the rigid limit, the numerical results recover the well-known Neugebauer function of the structure factor of a rigid rod. Based on the calculated structure factor, the random phase approximation is employed to study the physical properties of the order-disorder transition for asymmetric wormlike diblock copolymers; particularly, the spinodal line of the disordered phase is calculated. For the case of symmetric diblock copolymer microphase separation, the present calculation reproduces the phase boundary previously determined by self-consistent field theories and yields the entire picture crossing over from the flexible-chain limit to the rigid-chain limit.

Relationship between spin ordering, entropy, and anomalous lattice variation in Mn3Sn(1-ε)Si(ε)C(1-δ) compounds.

The crystal and magnetic structures of antiperovskite compounds Mn3SnC, Mn3Sn0.95C0.9, and Mn3Sn0.93Si0.07C0.94 were studied as a function of temperature and magnetic field by neutron powder diffraction. For Mn3SnC, the magnetic field induces a dramatic variation of antiferromagnetic moment and lattice parameter. Because of this spin-lattice coupling, the "square" antiferromagnetic (AFM) structure plays a key role in inducing a negative thermal expansion in the material. Moreover, the thermal expansion parameter is closely related to the rate of change of the AFM moment, which can be controlled by introducing vacancies or by doping. The variations of the AFM moment and lattice parameter in Mn3SnC with magnetic field make it possible to use the tunable properties for technical applications.

Two-dimensional photonic crystal sensor enabled by hydrophobic hydrogen-bonded organic Frameworks@Metal-Organic frameworks for trace nerve agents detection.

The development of fast and accurate sensors for nerve agents holds immense significance for homeland security and public health. However, the humidity interference from ambient environments and poor sensitivity for trace nerve agents are largely unsolved problems. To overcome the problems, a humidity-independent two-dimensional photonic crystal (2-D PC) sensor is developed by exploiting UiO-66-NH2 2-D PC with excellent sensitivity coupled to a hydrophobic hydrogen-bonded organic framework (HOFs) for detection sarin simulant dimethyl methyl phosphonate (DMMP). Selective sensing results show that the HOFs@UiO-66-NH2 2-D PC sensor presents the outstanding DMMP specificity, and the limit of detection (LOD) for DMMP response of the sensor can reach 508 ± 68 ppb at room temperature. Water-resistant experiments demonstrate that the HOFs@UiO-66-NH2 2-D PC sensor shows excellent stability even under 80% relative humidity (RH). Moreover, the sensor also exhibits a rapid response/recovery time of 1 s/3 s and can maintain excellent sensing performance under heat-treatment of 200 °C and in the long-term storage (30 days). The adsorption kinetics and the hydrogen bond interaction are conducted to elucidate the mechanism of enhanced sensing DMMP properties. These results indicate the potential application of the sensor in the trace nerve agent's detection, especially in humidity environment.

Three-dimensional photonic crystal optical gas sensor for trace detection and ultrafast response of chemical warfare agent in atmospheric humidity.

Chemical warfare agents (CWAs) are toxic that pose a threat to the environment and human health, even trace amounts of CWAs can be fatal. In view of this, there is an urgent need to develop gas sensors for trace detection and ultrafast response of CWAs. Herein, an optical gas sensor has been proposed based on metal-organic frameworks (MOFs) three-dimensional (3D) photonic crystal to detect trace CWAs' simulant (dimethyl methylphosphonate, DMMP) in different atmospheric humidity (RH 20 %, RH 40 %, RH 60 %, RH 80 %). At relative humidity (RH) of 20 %, the sensor shows excellent selectivity of DMMP due to the specific interactions of van der Waals force between UiO-67 and phosphoryl oxygen (OP) group of DMMP (C3H9O3P), the ultrahigh sensitivity (42.7 ppb), ultrafast response (0.5 s) are profit from the ordered superstructure of 3D photonic crystal and its complete photonic bandgap. At higher humidity (RH 40%-80 %), the sensor shows excellent stability, long-term repeatability, and it still keeps ultrahigh sensitivity (12.1 ppb), ultrafast response (0.49 s) for DMMP at RH 80 %. Moreover, an optical gas sensor array has been prepared to solve the problem of cross-sensitive between DMMP and other CWAs at highest humidity (RH ≥ 80 %), the average classification accuracy can reach 98.6 %.

Enhanced FK506 production in Streptomyces tsukubaensis by rational feeding strategies based on comparative metabolic profiling analysis.

FK506, a widely used immunosuppressant, is produced by industrial fermentation processes using various Streptomyces species. However, the low titer becomes a bottleneck for its application and industrialization. It urgently required a full understanding of the biological mechanisms for FK506 overproduction. Towards this end, comparative metabolomics approach was employed to analyze metabolite concentrations difference of Streptomyces tsukubaensis cultivated in two media with low and high productivities. Initially, 98 intracellular metabolites were identified and 13 metabolites involved in five pathways were determined to be directly correlated with FK506 biosynthesis. Then in-depth analysis elucidated how those key factors exerted influence on FK506 biosynthesis. Many previously unreported metabolites were shown to play an important role in FK506 biosynthesis and provided potential regulation points for external manipulation. Based on such key information, rationally designed feeding strategy was carried out. Results showed that the FK506 yield increased from 251 to 405 mg/L, whereas, by-products FK520 and 37,38-dihydro-FK506 decreased by 31% and 39%, respectively, compared with the values of control. To our knowledge, it is the first study to apply the comparative metabolomics method to identify key metabolites to promote the FK506 production. The strategies developed here can easily be extended to titer improvement of other important microbial natural products and process optimization.