On the Hermitian Positive Definite Solutions of Nonlinear Matrix Equation X

Nonlinear matrix equation Xs+A∗X−t1A+B∗X−t2B=Q has many applications in engineering; control theory; dynamic programming; ladder networks; stochastic filtering; statistics and so forth. In this paper, the Hermitian positive definite solutions of nonlinear matrix equation Xs+A∗X−t1A+B∗X−t2B=Q are considered, where Q is a Hermitian positive definite matrix, A, B are nonsingular complex matrices, s is a positive number, and 0<ti≤1, i=1,2. Necessary and sufficient conditions for the existence of Hermitian positive definite solutions are derived. A sufficient condition for the existence of a unique Hermitian positive definite solution is given. In addition, some necessary conditions and sufficient conditions for the existence of Hermitian positive definite solutions are presented. Finally, an iterative method is proposed to compute the maximal Hermitian positive definite solution, and numerical example is given to show the efficiency of the proposed iterative method

The advantage of point-of-care ultrasound in central venous catheterization and related pericardial effusion in infants in the NICU

BackgroundCentral venous catheterization (CVC) is broadly used in neonatal intensive care units (NICUs) for efficient vascular access; however, its establishment and maintenance are associated with numerous risks and complications. Here, we focus on investigating the value of point-of-care ultrasound (POCUS) in the early diagnosis and treatment of pericardial effusion associated with CVC and compare the differences in ultrasound and radiography in CVC localization and monitoring in the NICU.MethodsTwenty-five infants with CVC-associated pericardial effusion (PCE) who were hospitalized in the NICU of Peking University Third Hospital between January 2013 and March 2023 were retrospectively selected for the study. Data concerning their catheterization characteristics, CVC tip position, clinical and imaging manifestations of PCE, treatments, and prognoses were analyzed.ResultsThe mean gestational age of our cohort was 29.3 ± 3.1 weeks, and the mean birth weight was 1,211 ± 237 g. The incidence of CVC-associated PCE was 0.65%, and 80% of PCE cases occurred within 4 days of CVC. After PCE, the most common symptoms were tachypnea (44%) and tachycardia (64%). Chest radiographs revealed cardiothoracic enlargement, and only 2 cases (9.10%) showed a “flask heart”. Cardiac ultrasound showed that the catheter tip extended deep into the heart in 72% of infants with PCE. Cardiac insufficiency was observed in 12 cases (48%). Overall, 8 infants (32%) had pericardial tamponade, 7 (87.5%) of whom underwent pericardiocentesis. Overall, 2 (8%) infants died, and the remaining 23 (92%) were cured.ConclusionCVC-associated PCE mostly occurs in the early post-catheterization stages (within 4 days) in infants. Some cases may have critical clinical manifestations and progress rapidly, with some even developing pericardial tamponade. A CVC tip being deep into the heart cavity is an important cause of PCE. Compared with chest radiography, point-of-care ultrasound is more accurate for CVC tip positioning and can detect PCE more quickly. Furthermore, it is more advantageous for locating and monitoring CVC-associated PCE. Early identification and diagnosis can effectively reduce fatality rates and improve the prognosis of infants with CVC-associated PCE

Thermal decomposition of n-hexane in organic Rankine cycle: a study combined ReaxFF reactive molecular dynamic and density functional theory

The thermal decomposition mechanism of n-hexane is investigated by using density functional theory and ReaxFF force field. The initial decomposition reactions, the effect of temperature on thermal decomposition and first-order kinetics are analyzed. The results show that the C-C bonds in n-hexane molecule are more easily decomposed than that of C-H bonds, and the breakage of C3-C4 bond is the main initial decomposition reaction. The main decomposition products of n-hexane are H2, CH4, C2H2, C2H4, C2H6, and C3H6. The decomposition rate of n-hexane is accelerated by temperature. The apparent activation energy and pre-exponential factor of n-hexane thermal decomposition are 209.8 kJ mol−1 and 1.1 × 1013 s−1, respectively

Early transition from insulin to sulfonylureas in neonatal diabetes and follow-up: experience from China

Background: Sulfonylurea therapy can improve glycemic control and ameliorate neurodevelopmental outcomes in patients suffering from neonatal diabetes mellitus (NDM) with KCNJ11 or ABCC8 mutations. As genetic testing results are often delayed, it remains controversial whether sulfonylurea treatment should be attempted immediately at diagnosis or doctors should await genetic confirmation. Objective: This study aimed to investigate the effectiveness and safety of sulfonylurea therapy in Chinese NDM patients during infancy before genetic testing results were available. Methods: The medical records of NDM patients with their follow‐up details were reviewed and molecular genetic analysis was performed. Sulfonylurea transfer regimens were applied in patients diagnosed after May 2010, and glycemic status and side effects were evaluated in each patient. Results: There were 23 NDM patients from 22 unrelated families, 10 had KCNJ11 mutations, 3 harbored ABCC8 mutations, 1 had INS mutations, 4 had chromosome 6q24 abnormalities, 1 had a deletion at chromosome 1p36.23p36.12, and 4 had no genetic abnormality identified. Sixteen NDM infants were treated with glyburide at an average age of 49 days (range 14‐120 days) before genetic confirmation. A total of 11 of 16 (69%) were able to successfully switch to glyburide with a more stable glucose profile. The responsive glyburide dose was 0.51 ± 0.16 mg/kg/d (0.3‐0.8 mg/kg/d), while the maintenance dose was 0.30 ± 0.07 mg/kg/d (0.2‐0.4 mg/kg/d). No serious adverse events were reported. Conclusions: Molecular genetic diagnosis is recommended in all patients with NDM. However, if genetic testing results are delayed, sulfonylurea therapy should be considered before such results are received, even in infants with newly diagnosed NDM

Isolation, Purification, Identification and Hypolipidemic Activity of Lipase Inhibitory Peptide from Chlorella pyrenoidosa

In this study, pancrelipase inhibitory peptides (PES) from an enzymatic protein hydrolysate of Chlorella pyrenoidosa were isolated and purified by ultrafiltration and Sephadex gel chromatography. The in vivo hypolipidemic activity of PES was evaluated by fat deposition and the levels of triglyceride (TG) and total cholesterol (TC) in Caenorhabditis elegans fed a high sugar diet. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the peptide sequence of PES, and molecular docking was used to select potential pancreatic lipase inhibitory peptides, and the pancreatic lipase inhibitory activity of the synthesized peptides was verified. The results showed that PES had good hypolipidemic activity at a concentration of 1 mg/mL; it inhibited lipid deposition by 22.5%, and reduced the levels of TG and TC by 27.4% and 29.4%, respectively. In total, 999 peptides were identified, and four potential lipase inhibitory peptides were obtained. Among them, FLGPF had the best inhibitory effect on pancreatic lipase, with an inhibition rate of 50.12% at 8 mg/mL. The inhibition was reversible and non-competitive, with an inhibition constant of 5.23 mg/mL. Molecular docking showed that FLGPF could better bind to human pancreatic triacylglycerol lipase (PTL) via π-hydrogen, π-cation and hydrogen bond interactions. This study can provide a theoretical reference for the development and utilization of C. pyrenoidosa protein-derived hypolipidemic peptide

Nurse educators perceptions of simulation teaching in Chinese context: benefits and barriers

Background Although simulated teaching was introduced to China in the 1990s, it remains underused in nursing education. Determining how Chinese nurse educators feel about using simulation in their institutions is very important for faculty training and has the potential to influence simulation implementation. Method This cross-sectional descriptive study was undertaken to identify the nurse educators’ experiences in the use of simulation from various regions of China. One hundred and thirty-six nurse educators provided demographic data and information about simulation implementation within their institutions and explored the perceived barriers and benefits of simulation usage. Results The survey data shows that 108 participants have used simulation in their work, but less than 92 (67.6%) of the respondents had used this teaching strategy more than ten times in last year. The study identified four factors hindering nurse faculty from simulation adoption: (1) concerns with student readiness; (2) the need for faculty team-building for simulation teaching; (3) lack of adequate simulation resources; and (4) thoughtful integration of simulation into nursing curricula. Conclusions Study data suggest that faculty training programs for simulation should be based on the nurse educators’ training needs, including systematically designed training topics, and the provision of hands-on learning simulation activities with expert feedback to help nurse educators achieve the competencies required for effective simulation-based education

Family-clinician shared decision making in intensive care units : cluster randomized trial in China

We thank the China Medical Board, which financially supported our study.Objective To investigate if a Family-Clinician Shared Decision-Making (FCSDM) intervention benefits patients, families and intensive care units (ICUs) clinicians.  Methods Six ICUs in China were allocated to intervention or usual care. 548 patients with critical illness, 548 family members and 387 ICU clinicians were included into the study. Structured FCSDM family meetings were held in the intervention group. Scales of SSDM, HADS, QoL2 and CSACD were used to assess families’ satisfaction and distress, patients’ quality of life, and clinicians’ collaboration respectively.  Results Comparing the intervention group with the control group at post-intervention, there were significant differences in the families’ satisfaction (P =0.0001), depression level (P =0.005), and patients’ quality of life (P =0.0007). The clinicians’ mean CSCAD score was more positive in the intervention group than controls (P < 0.05). There was no significant between-group differences on ICU daily medical cost, but the intervention group demonstrated shorter number of days’ stay in ICU (P=0.0004).  Conclusion The FCSDM intervention improved families’ satisfaction and depression, shortened patients’ duration of ICU stay, and enhanced ICU clinicians’ collaboration.  Practice implications Further improvement and promotion of the FCSDM model are needed to provide more evidence to this field in China.Publisher PDFPeer reviewe

Efficacy and safety of molnupiravir in patients with Omicron variant vaccine breakthrough COVID-19 infection: a randomized, controlled trial

Introduction: Randomized, controlled trials of molnupiravir in real-world use during the Omicron wave are scarce. The frequency of hospitalization and death is low, so further research is needed to confirm the virological efficacy of molnupiravir.Methods: A single-center, randomized, controlled clinical trial was conducted, and 111 hospitalized coronavirus disease 2019 (COVID-19) patients were randomly assigned at a ratio of 1:1. Fifty-three patients in the molnupiravir group were administered 800 mg of molnupiravir twice daily for 5 days in addition to the standard therapy, and 58 patients in the control group only received the standard therapy in accordance with local guidelines. The antiviral effect and adverse events were evaluated during the follow-up.Results: The median viral clearance time in the molnupiravir group was significantly shorter than that in the control group (p = 0.003). Furthermore, patients who started molnupiravir therapy within 3 days had significantly shorter viral clearance time than the controls (p = 0.003). In the vaccinated subgroup, molnupiravir therapy was also associated with a shorter viral clearance time (p = 0.003). A total of three adverse events, which were minor, were reported in the molnupiravir group. One of the patients had mild liver function abnormalities, and all of them were resolved without intervention. However, the remission time was similar between the two tested groups.Conclusion: Molnupiravir exhibited good viral replication inhibitor efficacy in patients with Omicron variant vaccine breakthrough COVID-19 infection.Clinical Trial Registration: [https://www.chictr.org.cn/], identifier [ChiCTR2200059796]