Electrostatic force on a spherical particle confined between two planar surfaces.

A charge-free particle in a uniform electric field experiences no net force in an unbounded domain. A boundary, however, breaks the symmetry and the particle can be attracted or repelled to it, depending on the applied field direction [Z. Wang et al., Phys. Rev. E, 2022, 106, 034607]. Here, we investigate the effect of a second boundary because of its common occurrence in practical applications. We consider a spherical particle suspended between two parallel walls and subjected to a uniform electric field, applied in a direction either normal or tangential to the surfaces. All media are modeled as leaky dielectrics, thus allowing for the accumulation of free charge at interfaces, while bulk media remain charge-free. The Laplace equation for the electric potential is solved using a multipole expansion and the boundaries are accounted for by a set of images. The results show that in the case of a normal electric field, which corresponds to a particle between two electrodes, the force is always attractive to the nearer boundary and, in general, weaker that the case of only one wall. Intriguingly, for a given particle-wall separation we find that the force may vary nonmonotonically with confinement and its magnitude may exceed the one-wall value. In the case of tangential electric field, which corresponds to a particle between insulating boundaries, the force follows the same trends but it is always repulsive.

Eravacycline susceptibility was impacted by genetic mutation of 30S ribosome subunits, and branched-chain amino acid transport system II carrier protein, Na/Pi cotransporter family protein in Staphylococcus aureus.

BACKGROUND: Our previous research indicated the excellent in vitro antibacterial activity of Eravacycline (Erava) and its heteroresistance frequency against clinical Staphylococcus aureus isolates. In this study, we further aimed to investigate the mechanisms of Erava resistance and heteroresistance in S. aureus. Eight parental S. aureus isolates were induced under Erava pressure in vitro and the Erava-resistant isolates were selected and identified. Then, the genetic mutations of 30S ribosomal subunits were analyzed by PCR and sequence alignment. RT-qPCR analysis were performed to compare the relative expression of eight candidate genes impacting the susceptibility of tetracycline (Tet) between the resistant or heteroresistant and parental isolates. Furthermore, the in vitro overexpression vectors of three selected candidate genes were constructed to test their impact on the heteroresistance and resistance of Erava in S. aureus. RESULTS: The MICs elevation in Erava-induced resistant S. aureus isolates were identified and the increasing MICs values of another two Tet class antibiotics, including both omadacycline (Omada) and tigecycline (Tige) were also tested. Genetic mutations in 30S ribosomal protein S10 were found frequently in Erava-derived resistant isolates. RT-qPCR analysis and the in vitro overexpression experiments indicated that USA300HOU_RS00550 (an Na/Pi cotransporter family protein) and USA300HOU_RS01625 (a branched-chain amino acid transport system II carrier protein) contributed to Erava heteroresistance in S. aureus. CONCLUSION: Genetic mutation of 30S ribosome subunits contributed to Erava resistance, and the transcriptional overexpression of USA300HOU_RS01625 and USA300HOU_RS00550 also participated in the occurrence of Erava heteroresistance in S. aureus.

Three-dimensional characterization of the microstructure in rabbit patella-patellar tendon interface using propagation phase-contrast synchrotron radiation microtomography.

Understanding the three-dimensional ultrastructure morphology of tendon-to-bone interface may allow the development of effective therapeutic interventions for enhanced interface healing. This study aims to assess the feasibility of propagation phase-contrast synchrotron radiation microtomography (PPC-SRµCT) for three-dimensional characterization of the microstructure in rabbit patella-patellar tendon interface (PPTI). Based on phase retrieval for PPC-SRµCT imaging, this technique is capable of visualizing the three-dimensional internal architecture of PPTI at a cellular high spatial resolution including bone and tendon, especially the chondrocytes lacuna at the fibrocartilage layer. The features on the PPC-SRµCT image of the PPTI are similar to those of a histological section using Safranin-O staining/fast green staining. The three-dimensional microstructure in the rabbit patella-patellar tendon interface and the spatial distributions of the chondrocytes lacuna and their quantification volumetric data are displayed. Furthermore, a color-coding map differentiating cell lacuna in terms of connecting beads is presented after the chondrocytes cell lacuna was extracted. This provides a more in-depth insight into the microstructure of the PPTI on a new scale, particularly the cell lacuna arrangement at the fibrocartilage layer. PPC-SRµCT techniques provide important complementary information to the conventional histological method for characterizing the microstructure of the PPTI, and may facilitate in investigations of the repair mechanism of the PPTI after injury and in evaluating the efficacy of a different therapy.

Demystifying COVID-19 mortality causes with interpretable data mining.

While COVID-19 becomes periodical, old individuals remain vulnerable to severe disease with high mortality. Although there have been some studies on revealing different risk factors affecting the death of COVID-19 patients, researchers rarely provide a comprehensive analysis to reveal the relationships and interactive effects of the risk factors of COVID-19 mortality, especially in the elderly. Through retrospectively including 1917 COVID-19 patients (102 were dead) admitted to Xiangya Hospital from December 2022 to March 2023, we used the association rule mining method to identify the risk factors leading causes of death among the elderly. Firstly, we used the Affinity Propagation clustering to extract key features from the dataset. Then, we applied the Apriori Algorithm to obtain 6 groups of abnormal feature combinations with significant increments in mortality rate. The results showed a relationship between the number of abnormal feature combinations and mortality rates within different groups. Patients with "C-reactive protein > 8 mg/L", "neutrophils percentage > 75.0 %", "lymphocytes percentage < 20%", and "albumin < 40 g/L" have a 2 × mortality rate than the basic one. When the characteristics of "D-dimer > 0.5 mg/L" and "WBC > 9.5 × 10 9 /L" are continuously included in this foundation, the mortality rate can be increased to 3 × or 4 × . In addition, we also found that liver and kidney diseases significantly affect patient mortality, and the mortality rate can be as high as 100%. These findings can support auxiliary diagnosis and treatment to facilitate early intervention in patients, thereby reducing patient mortality.

Cell-based tissue engineered flexor tendon allograft: A canine in vivo study.

This study aimed to compare the clinically established autologous extrasynovial tendon graft to a newly developed tissue-engineered allograft (Eng-allograft) in terms of functional outcomes following flexor tendon reconstruction in a canine model. The second and fifth flexor digitorum profundus (FDP) tendons from 16 dogs were transected and repaired in Zone II. After 6 weeks of cage activity, the repaired tendons were intentionally ruptured, creating a clinically relevant model for reconstruction. The re-ruptured FDP tendons were then reconstructed using either the clinically standard autologous extrasynovial tendon graft or the Eng-allograft, which had been revitalized with autologous bone marrow-derived mesenchymal stem cells (BMSCs) and synovialized using carbodiimide derivatized synovial fluid (cd-SYN). Following 12 weeks of postoperative rehabilitation, the functional outcomes of the surgical digits were evaluated. The Eng-allograft group exhibited improved digital function, including lower digit work of flexion and reduced adhesion status, while maintaining similar tendon gliding resistance compared to the autograft group. However, the failure load of both the distal and proximal host/graft conjunctions in the Eng-allograft group was significantly lower than that of the autograft group with higher graft rupture at the host-graft junction. In conclusion, the decellularized allogenic intrasynovial tendon, when revitalized BMSCs and synovialized with cd-SYN, demonstrates positive effects on digital function improvement and adhesion reduction. However, the healing at both proximal and distal graft/host junctions is far lower than the autograft. Further research is needed to enhance the healing capacity of allograft conjunctions, aiming to achieve a comparable level of healing seen with autografts.

Characterizing distinct profiles of immune and inflammatory response with age to Omicron infection.

Background: Understanding inflammatory and immune responses to Omicron infection based on age is crucial when addressing this global health threat. However, the lacking of comprehensive elucidation hinders the development of distinct treatments tailored to different age populations. Methods: 1299 cases of Omicron infection in Shanghai were enrolled between April 10, 2022 and June 3, 2022, dividing into three groups by ages: Adult group (18-59 years), Old group (60-79 years), and Elder group (≥ 80 years). Laboratory data including inflammatory cytokines, cellular, and humoral immunity were collected and analyzed. Results: The mean age of Adult, Old, and Elder groups were 44.14, 69.98, and 89.35 years, respectively, with 40.9% being men. The Elder group patients exhibited higher white blood cell (WBC) counts and elevated levels of inflammatory cytokines, but their lymphocyte counts were relatively lower. In comparison to the Old group patients, the Elder group patients demonstrated significantly lower CD3+ T-cell counts, CD3+ T-cell proportion, CD4+ T-cell counts, CD8+ T-cell counts, and CD19+ B-cell counts, while the NK-cell counts were higher. Omicron negative patients displayed a higher proportion of CD19+ B-cells and higher levels of Complement-3 and IL-17 compared to the positive patients in the Old group. Omicron negative patients had lower WBC counts, CD3+CD8+ T-cells proportion, and the levels of serum amyloid A and IgA in the Elder group, but the CD4+/CD8+ ratio was higher. Conclusions: Our study identified the distinct profiles of inflammatory and immune responses to Omicron infection varying with age and highlighted the diverse correlations between the levels of various biomarkers and Omicron infected/convalescent patients.

Decoding molecular signature on heart of septic mice with distinct left ventricular ejection fraction.

Dysregulated cardiac function after sepsis in intensive care unit is known to predict poor long-term outcome and increase mortality. Their pathological feature and molecular mechanism remain unclear. We observed that septic patients with depressed left ventricular ejection fraction (LVEF) have the highest in-hospital and 28 days mortality comparing to patients with hyperdynamic LVEF or with heart failure with preserved LVEF. Echocardiograms reveal that survivors post cecum ligation and puncture (CLP) on rodents have stable LVEF and non-survivors have fluctuated LVEF at CLP early phase. CLP-induced mice fall into three groups based on LVEF 24 h post-surgery: high-, low-, and normal-LVEF. Transcriptomic and proteomic analyses identify jointly and distinctively changed genes, proteins and biologically essential pathways in left ventricles from three CLP groups. Notably, transmission electron microscopy shows different mitochondrial and sarcomere defects associated with LVEF variances. Together, this study systematically characterizes the molecular, morphological, and functional alterations in CLP-induced cardiac injury.

Chinese experts' consensus on the application of intensive care big data.

The development of intensive care medicine is inseparable from the diversified monitoring data. Intensive care medicine has been closely integrated with data since its birth. Critical care research requires an integrative approach that embraces the complexity of critical illness and the computational technology and algorithms that can make it possible. Considering the need of standardization of application of big data in intensive care, Intensive Care Medicine Branch of China Health Information and Health Care Big Data Society, Standard Committee has convened expert group, secretary group and the external audit expert group to formulate Chinese Experts' Consensus on the Application of Intensive Care Big Data (2022). This consensus makes 29 recommendations on the following five parts: Concept of intensive care big data, Important scientific issues, Standards and principles of database, Methodology in solving big data problems, Clinical application and safety consideration of intensive care big data. The consensus group believes this consensus is the starting step of application big data in the field of intensive care. More explorations and big data based retrospective research should be carried out in order to enhance safety and reliability of big data based models of critical care field.

Particle-surface interactions in a uniform electric field.

The electrostatic force on a spherical particle near a planar surface is calculated for the cases of a uniform electric field applied in either normal or tangential direction to the surface. The particle and suspending media are assumed to be weakly conducting, so that that the leaky dielectric model applies. The Laplace equation for the electric potential is solved in bipolar coordinate system and the potential is obtained in terms of a series expansion of Legendre polynomials. The force on the particle is calculated using the Maxwell tensor. We find that in the case of normal electric field, which corresponds to a particle near an electrode, the force is always attractive but at a given separation it varies nontrivially with particle-suspending medium conductivity ratio; the force on a particle that is more conducting than the suspending medium is much larger compared to the force on a particle less conducing than the suspending medium. In the case of tangential electric field, which corresponds to a particle near an insulating boundary, the force is always repulsive.

Application of Transumbilical Laparoscopic Surgery on Low/Ultralow Rectal Cancer for Anal Sphincter Preservation.

Background: Rectal cancer is a common malignant tumor in the gastrointestinal tract. This work compares the effects of transumbilical laparoscopic surgery (TULS) and laparoscopic-assisted surgery on the anus-preserving effect of low/ultralow rectal cancer. Materials and Methods: Eighty patients with rectal cancer admitted to our hospital from February 2011 to July 2016 were randomly selected and divided into the laparoscopic group and TULS group, 40 cases in each group, all underwent radical anorectal cancer radical surgery. Statistical analysis was performed on surgical-related indicators in the two groups. Results: Two patients converted to open surgery were excluded. Five patients were excluded because of radical abdomen perineal resection for rectal cancer. Six patients were converted to TULS from laparoscopic surgery. Sixty-seven patients in the experimental group successfully completed anus-sparing surgery, and none died during the operation. The compliance rate of the distance between the lower edge of the tumor and the incision edge of the specimen in the TULS group was better than that in the laparoscopic group (P < .05). There were no significant differences between the two groups in terms of surgical time, blood loss, number of lymph node dissections, functional time of voluntary defecation and postoperative complications, tumor-free recurrence rate at 3 years, and 3-year survival rate after surgery (P > .05). Conclusions: The TULS method is safe and feasible in low and ultralow rectal cancer surgery. It has more advantages than laparoscopic-assisted surgery for anus preservation.