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In this paper we study a fourth-order differential equation with Riemann-Stieltjes integral boundary conditions. We consider two cases, namely when the nonlinearity satisfies superlinear growth conditions (we use topological degree to obtain an existence theorem on nontrivial solutions), when the nonlinearity satisfies a one-sided Lipschitz condition (we use the method of upper-lower solutions to obtain extremal solutions).

This paper focuses on a two-component interacting system introduced by Popowicz, which has the coupling form of the Camassa–Holm and Degasperis–Procesi equations. Using distribution theory, single peakon solutions and several double peakon solutions of the system are described in an explicit expression. Moreover, dynamic behaviors of several types of double peakon solutions are illustrated through figures. In addition, the persistence properties of the solutions to the Popowicz system in weighted Lp spaces is considered via a large class of moderate weights.

The kinetics of leaching zinc from hemimorphite was investigated. The factors that influence hemimorphite leaching were also evaluated, and a kinetic model was built. In addition, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was used to investigate the changes of surface morphology before and after leaching. By decreasing particle size and increasing temperature, 5-sulfosalicylic acid concentration, and stirring speed, the leaching rate of hemimorphite can be enhanced. The shrinkage nucleus model describes the surface chemistry of leaching. The activation energy of hemimorphite by 5-sulfosalicylic acid in the leaching process was determined as 55.244 kJ/mol. The reaction rate based on the shrinkage nucleus model can be expressed by the semi-empirical formula:1−1−x1/3 =[k0C0.3385(r0)−0.6083(SS)0.4992exp(−55.244/RT)]t. At the condition of 50 °C of leaching temperature, 0.175 mol/L of 5-sulfosalicylic acid concentration, 82.5 μm of particle size and 650 rpm of stirring speed, the high leaching rates of zinc were obtained. After the reaction time of 15 min, the leaching rate of zinc reached more than 95%. According to the SEM-EDS results, the hemimorphite and leaching residue are distributed in blocks, but the particle size of the leaching residue is smaller, and the atomic concentrations of Zn and Si in the leaching residue are significantly lower than those in the hemimorphite, so the leaching effect is remarkable. Therefore, 5-sulfosalicylic acid solution would be an excellent leaching agent for zinc extraction from hemimorphite.

In this paper, we focus on a class of Hadamard type fractional differential system involving Hadamard type fractional derivatives on an infinite interval. By utilizing the monotone iterative technique and Banach's contraction mapping principle, some explicit monotone iterative sequences for approximating the extreme positive solutions and the unique positive solution for the system are constructed.

Tangential leakage loss is the primary factor that significantly affects the output performance of oil-free scroll expanders. A scroll expander can function under different operating conditions, and the flow of tangential leakage and generation mechanism is different. This study employed computational fluid dynamics to investigate the unsteady flow characteristics of the tangential leakage flow of a scroll expander with air as the working fluid. Consequently, the effects of different radial gap sizes, rotational speeds, inlet pressures, and temperatures on the tangential leakage were discussed. The tangential leakage decreased with increases in the scroll expander rotational speed, inlet pressure, and temperature, and decreased with decrease in radial clearance. With an equal-proportional increase in radial clearance, the flow form of the gas in the first expansion and back-pressure chambers became more complicated; when the radial clearance increased from 0.2 to 0.5 mm, the volumetric efficiency of the scroll expander decreased by approximately 5.0521%. Moreover, because of the large radial clearance, the tangential leakage flow maintained a subsonic flow. Further, the tangential leakage decreased with increase in rotational speed, and when the rotational speed increased from 2000 to 5000 r/min, the volumetric efficiency increased by approximately 8.7565%.

In this paper, we introduce new sequential fractional differential equations with mixed-type boundary conditions CDq+kCDq−1ut=ft,ut,CDq−1ut,t∈0,1,α1u0+β1u1+γ1Iruη=ε1,η∈0,1,α2u′0+β2u′1+γ2Iru′η=ε2, where q∈1,2 is a real number, k,r>0,αi,βi,γi,εi∈ℝ,i=1,2,CDq is the Caputo fractional derivative, and the boundary conditions include antiperiodic and Riemann-Liouville fractional integral boundary value cases. Our approach to treat the above problem is based upon standard tools of fixed point theory and some new inequalities of norm form. Some existence results are obtained and well illustrated through the aid of examples.

In this paper, we present some theorems on impulsive periodic boundary value problems with fractional derivative dependence. In particular, we discuss the existence of solutions of a class of fractional-order impulsive periodic boundary values with nonlinear terms and impulsive terms satisfying certain growth conditions. Three examples are provided to illustrate our results.

In this paper, we study the existence of nontrivial solutions for the 2nth Lidstone boundary value problem with a sign-changing nonlinearity. Under some conditions involving the eigenvalues of a linear operator, we use the topological degree theory to obtain our main results.

In this paper, we use fixed-point index to study the existence of positive solutions for a system of Hadamard fractional integral boundary value problems involving nonnegative nonlinearities. By virtue of integral-type Jensen inequalities, some appropriate concave and convex functions are used to depict the coupling behaviors for our nonlinearities fii=1, 2.

In this paper, we study the existence of nontrivial solutions for a system of fractional q-difference equations involving q-integral boundary conditions, and we use the topological degree to establish our main results by considering the first eigenvalue of some associated linear integral operators.

By constructing some general type conditions and using fixed point theorem of cone, this paper investigates the existence of at least one and at least two positive solutions for systems of nonlinear higher order differential equations with integral boundary conditions. As application, some examples are given.

We investigate the existence of positive solutions for a nonlinear higher order differential system, where the differential system is coupled not only in the differential system but also through the boundary conditions. By constructing a special cone and using the fixed point theorem of cone expansion and compression of norm type, the existence of single and multiple positive solutions is established. As an application, we give some examples to demonstrate our results.

We study the existence of multiple positive solutions for nth-order multipoint boundary value problem. u(n)(t)+a(t)f(u(t))=0, t∈(0,1), u(j-1)(0)=0(j=1,2,…,n-1), u(1)=∑i=1mαiu(ηi), where n≥2, 00,i=1,2,…,m. We obtained the existence of multiple positive solutions by applying the fixed point theorems of cone expansion and compression of norm type and Leggett-Williams fixed-point theorem. The results obtained in this paper are different from those in the literature.

Abstract Background Recent studies have shown that deficient mismatch repair (dMMR) rectal cancer may be related to treatment resistance, resulting in a worse prognosis than proficient MMR (pMMR) rectal cancer. The purpose of this study was to explore whether surgery plus other treatments (radiotherapy and chemotherapy) can bring more benefits to these patients than surgery alone. Methods A retrospective study of 168 patients with rectal adenocarcinoma who underwent total mesorectal excision was conducted using immunohistochemical methods to determine MMR status and a propensity score matching model to minimize potential confounding factors between subgroups of patients with different treatment regimens. Kaplan–Meier analysis, log-rank tests, and Cox regression models were used to assess overall survival (OS) and disease-free survival (DFS) in patient subgroups. Results Only 6.9% (n = 168) of patients in the total cohort had dMMR rectal adenocarcinoma, and the most common cause of dMMR was a PMS2 deletion (103, 61.3%). The median DFS of the surgery alone group was 45.7 months (IQR, 40.9 to 77.8), and the median DFS of the surgery plus other treatment group was 43.9 months (IQR, 14.2 to 80.1). The surgery alone group was superior to the surgery plus other treatment group (HR, 0.16; 95% CI, 0.07 to 0.38; p = 0.005). There was no significant difference in OS (45.8 (IQR, 41.0 to 79.8) vs. 45.9 (IQR, 38.5 to 80.3)) between the two groups (HR, 0.57; 95% CI, 0.23 to 1.40; p = 0.263). Conclusions For patients with locally advanced dMMR rectal adenocarcinoma, compared with surgery alone, surgery plus other treatment options (radiotherapy and chemotherapy) do not grant long-term survival benefits but rather shorten DFS.

Abstract We evaluate the prognostic value of chemotherapy and other prognostic factors on overall survival among colon patients with deficient mismatch repair (dMMR), and determine the optimum time to start chemotherapy after surgery. Data of 306 colon cancer patients with dMMR who received radical surgery were collected from three Chinese centers between August 2012 and January 2018. Overall survival (OS) was assessed with the Kaplan–Meier method and log-rank. Cox regression analysis were used to assess influencing prognosis factors. The median follow-up time for all patients was 45.0 months (range, 1.0–100). There was a nonsignificant OS benefit from chemotherapy for patients with stage I and stage II disease, including high-risk stage II disease (log-rank p: 0.386, 0.779, 0.921), and a significant OS benefit for patients with stage III and stage IV disease for receiving post-operation chemotherapy (log-rank p = 0.002, 0.019). Stage III patients benefitted from chemotherapy regimens that contained oxaliplatin (log-rank p = 0.004), and Starting chemotherapy with oxaliplatin treatment earlier resulted in better outcomes (95% CI 0.013–0.857; p = 0.035). Chemotherapy regimens containing oxaliplatin can prolong the survival time of stage III and IV dMMR colon cancer patients. This beneficial manifestation was more pronounced after starting chemotherapy treatment early post operation. High risk stage II dMMR colon patients including T4N0M0 cannot benefit from chemotherapy.

The whitening and loss of brown adipose tissue (BAT) during obesity and aging promote metabolic disorders and related diseases. The imbalance of Ca2+ homeostasis accounts for the dysfunction and clearance of mitochondria during BAT whitening. Capsaicin, a dietary factor activating TRPV1, can inhibit obesity induced by high-fat diet (HFD), but whether capsaicin inhibits BAT loss and the underlying mechanism remain unclear. In this study, we determined that the inhibitory effects of capsaicin on HFD-induced obesity and BAT whitening were dependent on the participation of SIRT3, a critical mitochondrial deacetylase. SIRT3 also mediated all of the beneficial effects of capsaicin on alleviating reactive oxygen species generation, elevating mitochondrial activity, and restricting mitochondrial calcium overload induced by HFD. Mechanistically, SIRT3 inhibits mitochondrial calcium uniporter (MCU)-mediated mitochondrial calcium overload by reducing the H3K27ac level on the MCU promoter in an AMPK-dependent manner. In addition, HFD also inhibits AMPK activity to reduce SIRT3 expression, which could be reversed by capsaicin. Capsaicin intervention also inhibited aging-induced BAT whitening through this mechanism. In conclusion, this study emphasizes a critical role of the AMPK/SIRT3 pathway in the maintenance of BAT morphology and function and suggests that intervention in this pathway may be an effective target for preventing obesity- or age-related metabolic diseases. [ABSTRACT FROM AUTHOR]

Abstract Background We evaluated the prognostic role of deficient mismatch repair (dMMR) systems in stage II and stage III colon cancer patients during different postoperative periods. We also assessed whether patients aged ≥75 could benefit from chemotherapy. Methods This retrospective study was conducted across three medical centers in China. Kaplan–Meier survival methods and Cox proportional hazards models were used to evaluate the differences in overall survival (OS) and disease-free survival (DFS) rates. Propensity score matching was performed to reduce imbalances in the baseline characteristics of the patients. Landmark analysis was performed to evaluate the role of dMMR during different postoperative periods. Results The median follow-up time for all patients was 45.0 months (25–75 IQR: 38.0–82.5). There was no significant OS (p = 0.350) or DFS (p = 0.752) benefit associated with dMMR for stage II and III patients during the first postoperative year. However, significant OS (p

BackgroundNeck-shoulder pain is one of the most common discomfort symptoms among nursing staff, mostly caused by a heavy workload, restricted workstation, and prolonged poor posture.ObjectiveTo investigate the prevalence of neck-shoulder pain among nursing staff in tertiary general hospitals in Hunan Province, and to analyze workload-related risk factors.MethodsFrom October to December 2018, a multi-stage stratified randomized cluster sampling method was adopted to select a total of 1 200 nursing staff who met the inclusion andexclusion criteria in six tertiary general hospitals from five geographic subdivisions of Hunan Province were selected. A self-designed questionnaire was used to collect demographic characteristics, and past 1-month prevalence of neck-shoulder pain, a neck disability index (NDI) was used to assess the impact of neck pain on daily life, and functional disability was graded by the index of impaired neck function; a self-designed questionnaire was adopted to evaluate potential workload-related risk factors (working time, postural load, and force load) of neck-shoulder pain after a Delphi expert consultation. A total of 1 161 valid questionnaires were returned, and χ２test and logistic regression model were used to screen the potential risk factors for neck-shoulder pain.ResultsThe prevalence rate of neck-shoulder pain in the past 1 month was 87.5% (1 016/1 161) and varied by different characteristics of the nursing staff, ranging from 76.9% to 91.2%. The scores of the 10 items of the NDI ranged from 0 to 5, but most of them were 0, 1, and 2; of the 10 items, neck pain had the greatest impact on sleep (1.30±1.21) and the least impact on self-care behaviors (0.35±0.65). The index of impaired neck function showed that the majority (65.4%) of nurses had mild cervical spine dysfunction and 30.1% had moderate cervical spine dysfunction. The univariate analysis results revealed that 24 out of the 31 workload-related risk factors had significant differences, and further multiple analysis results showed that three variables entered the logistic regression model. Under the same conditions, nurses with ≥5 h of cumulative head-down tasks per shift had 3.03 times higher neck-shoulder pain risks compared with those with ＜1 h. Compared with “occasionally or never”, nurses who “sometimes” and “often” tilted their necks back and maintained this posture for a long time showed 2.36 and 2.94 times higher risks for neck-shoulder pain respectively. The nurses who reported “sometimes” and “often” having difficulty using their force at work due to unnatural posture had 2.78 times and 7.08 times higher neck-shoulder pain risks than those who “occasionally or never” respectively.ConclusionThe reported rate of neck-shoulder pain among nurses in tertiary general hospitals in Hunan Province is high, but most of them are mild dysfunction. Working hours and posture load may affect the risk of neck-shoulder pain.

ObjectiveParkinson's disease (PD) is a neurodegenerative syndrome, and deep-brain stimulation (DBS) is an effective therapy for carefully screened patients with PD. However, delayed recovery after anesthesia, which occurs after taking prolonged general anesthesia for such patients, has been reported less frequently in literature. This report explores the possible causes of postoperative awakening delay in patients undergoing DBS surgery due to general anesthesia and provides a reference for anesthesia management of similar operations in the future.Case PresentationThree patients with PD elective underwent DBS surgery. The first patients demonstrated walking disability, gait deficits, unstable posture, limb stiffness, and imbalance. The second demonstrated left limb static tremor, stiffness, and bradykinesia. The third demonstrated bradykinesia, rigidity, walking deficits, and decreased facial expression. These included two males and one female with a mean patient age of 60.7 ± 6.7year, weight of 63.7 ± 11 kg, the height of 163.3 ± 7.6 cm, and preoperative American Society of Anesthesiology rating of 2.3 ± 0.6. The preoperative Glasgow Coma Scale mean score was 15. All patients completed the operation under general anesthesia (the mean anesthesia time was 5.3 ± 1.1 h). The mean operation time was 252 ± 60 min. The mean bleeding volume was 50 ml, and the urine volume was 867 ± 569 ml. However, all the patients showed unconsciousness after 95 ± 22 min after stopping the anesthetic, and the respiratory function was in good condition, but they could not cooperate with anesthesiologists and had no response to the anesthesiologist's instructions. The mean hospital stay was 17 ± 7 days. All patients were discharged uneventfully. The average number of days patients followed up postoperatively was 171 ± 28.5 days. Motor and speech were improved significantly postoperatively in three patients compared with preoperatively. Taking anti-Parkinson medication was markedly reduced. There were no complications during postoperative follow-up.ConclusionsTo prevent delayed recovery occurring after DBS surgery in Parkinson's disease, it is recommended to take scalp nerve block + general anesthesia to complete the procedure while avoiding general anesthesia.

By using the Banach contraction principle and the Leggett-Williams fixed point theorem, this paper investigates the uniqueness and existence of at least three positive solutions for a system of mixed higher-order nonlinear singular differential equations with integral boundary conditions: *** where the nonlinear terms fi, gi satisfy some growth conditions, ßi[.] are linear functionals given by ßi[w] = ***, involving Stieltjes integrals with positive measures, and i = 1, 2. We give an example to illustrate our result. [ABSTRACT FROM AUTHOR]

Dissoluble magnesium alloys for fabrication of fracturing tools have received increasing attention in recent years. However, most of the existing research is focused on the small-sized samples prepared in the laboratory, and there is almost no report on the industrial dissoluble magnesium alloys. In this study, large-scale Mg-Al-Zn-Mn-Ca-Ni alloys with a diameter of 110 mm were prepared by a semi-continuous casting and two-step extrusion method, and the corresponding microstructure and mechanical and corrosion properties were also investigated. It was found that after two-step extrusion, the mainly precipitate phases in the Mg-Al-Zn-Mn-Ca-Ni alloy are bulk-like AlMnNi, strip-like Al3Ni, and granular-like and lamellar-like Mg17Al12 phases. Due to the combined effects of grain refinement and precipitation strengthening, the Mg-Al-Zn-Mn-Ca-Ni alloy obtained excellent mechanical properties after two-step extrusion, and its ultimate tensile strength, yield strength, and elongation were 314.6 MPa, 191.2 MPa, and 13.1%, respectively. Moreover, the corrosion rate of the alloy in 3 wt.% KCl at 93 °C was as high as 97.61 mg·cm−2·h−1. This work provides a high-performance, low-cost, and large-scale alloy product for the fabrication of dissoluble fracturing tools.

ObjectivesWe aimed to gain a better understanding of patients’ practice of hand hygiene (HH) and their knowledge and attitudes.DesignA cross-sectional survey.SettingA 3500-bed university-affiliated medical hospital in China.ParticipantsInpatients and their family members or caregivers.MethodsAn anonymous, self-reported questionnaire were used to collect data.ResultsA total of 376 questionnaires were issued, and 310 respondents completed it. Of the 310 respondents, 47.4% had received HH education, and 13.5% had a completing understanding of HH. A majority of patients believed that handwashing was important for disease recovery, and that it could prevent infection development. A total of 62.3% of patients washed their hands