Analysis of Transient Thermoacoustic Characteristics and Performance in Carbon Nanotube Sponge Underwater Transducers.

Recent advancements in marine technology have highlighted the urgent need for enhanced underwater acoustic applications, from sonar detection to communication and noise cancellation, driving the pursuit of innovative transducer technologies. In this paper, a new underwater thermoacoustic (TA) transducer made from carbon nanotube (CNT) sponge is designed to achieve wide bandwidth, high energy conversion efficiency, simple structure, good transient response, and stable sound response, utilizing the TA effect through electro-thermal modulation. The transducer has potential application in underwater acoustic communication. An electro-thermal-acoustic coupled simulation for the open model, sandwich model, and encapsulated model is presented to analyze the transient behaviors of CNT sponge TA transducers in liquid environments. The effects of key design parameters on the acoustic performances of both systems are revealed. The results demonstrate that a short pulse excitation with a low duty cycle could greatly improve the heat dissipation of the encapsulated transducer, especially when the thermoacoustic response time becomes comparable to thermal relaxation time.

NKUT: Dataset and Benchmark for Pediatric Mandibular Wisdom Teeth Segmentation.

Germectomy is a common surgery in pediatric dentistry to prevent the potential dangers caused by impacted mandibular wisdom teeth. Segmentation of mandibular wisdom teeth is a crucial step in surgery planning. However, manually segmenting teeth and bones from 3D volumes is time-consuming and may cause delays in treatment. Deep learning based medical image segmentation methods have demonstrated the potential to reduce the burden of manual annotations, but they still require a lot of well-annotated data for training. In this paper, we initially curated a Cone Beam Computed Tomography (CBCT) dataset, NKUT, for the segmentation of pediatric mandibular wisdom teeth. This marks the first publicly available dataset in this domain. Second, we propose a semantic separation scale-specific feature fusion network named WTNet, which introduces two branches to address the teeth and bones segmentation tasks. In WTNet, We design a Input Enhancement (IE) block and a Teeth-Bones Feature Separation (TBFS) block to solve the feature confusions and semantic-blur problems in our task. Experimental results suggest that WTNet performs better on NKUT compared to previous state-of-the-art segmentation methods (such as TransUnet), with a maximum DSC lead of nearly 16%. Dataset and codes will be released at https://github.com/nkicsl/NKUT.

A Phase Field Approach to Two-Dimensional Quasicrystals with Mixed Mode Cracks.

Quasicrystals (QCs) are representatives of a novel kind of material exhibiting a large number of remarkable specific properties. However, QCs are usually brittle, and crack propagation inevitably occurs in such materials. Therefore, it is of great significance to study the crack growth behaviors in QCs. In this work, the crack propagation of two-dimensional (2D) decagonal QCs is investigated by a fracture phase field method. In this method, a phase field variable is introduced to evaluate the damage of QCs near the crack. Thus, the crack topology is described by the phase field variable and its gradient. In this manner, it is unnecessary to track the crack tip, and therefore remeshing is avoided during the crack propagation. In the numerical examples, the crack propagation paths of 2D QCs are simulated by the proposed method, and the effects of the phason field on the crack growth behaviors of QCs are studied in detail. Furthermore, the interaction of the double cracks in QCs is also discussed.

Design and characteristic analysis of flexible CNT film patch for potential application in ultrasonic therapy.

Ultrasonic therapy has drawn increasing attention due to its noninvasiveness, great sensitivity and strong penetration capabilities. However, most of traditional rigid ultrasonic probes cannot achieve a solid interfacial contact with irregular nonplanar surfaces, which leads to unstable therapeutic effects and limitations of widespread use in practical applications. In this paper, a new flexible ultrasonic patch based on carbon nanotube (CNT) films is designed and fabricated to achieve a potential application in ultrasonic therapy. This patch is composed of a CNT film, a thermal protective layer and a heat sinking layer, and has the advantages of simple structure, soft, ultrathin and completely conforming to the treatment area. Theoretical and experimental studies are performed to investigate the acoustic and temperature fields before and after deformation. Effects of key design parameters of the patch on acoustic performances and temperature distributions are revealed. Numerical results indicate that the CNT film patch can produce ultrasounds over a wide frequency range and temperatures under the threshold of burn injury whether it is bent or not. Furthermore, it is also noted that the sound waves emitted from the bending patch are focused at the center of the bending patch, which demonstrates that the target treatment area can be controlled.

Clinicopathological characteristics and prognostic factors of cervical adenocarcinoma.

We aimed to assess the clinicopathological features and to determine the prognostic factors of cervical adenocarcinoma (AC). Relevant data were extracted from surveillance, epidemiology and end results database from 2004 to 2015. The log-rank test and Cox proportional hazard analysis were subsequently utilized to identify independent prognostic factors. A total of 3102 patients were identified. The enrolled patients were characterized by higher proportion of early FIGO stage (stage I: 65.9%; stage II: 14.1%), low pathological grade (grade I/II: 49.1%) and tumor size ≤ 4 cm (46.8%). The 5- and 10-year cancer-specific survival rates of these patients were 74.47% and 70.00%, respectively. Meanwhile, the 5- and 10-year overall survival (OS) rates were 71.52% and 65.17%, respectively. Multivariate analysis revealed that married status, surgery as well as chemotherapy were independent favorable prognostic indicators. Additionally, aged > 45, tumor grade III/IV, tumor size > 4 cm, advanced FIGO stage and pelvic lymph node metastasis (LNM) were unfavorable prognostic factors (all P < 0.01). Stratified analysis found that patients without surgery could significantly benefit from chemotherapy and radiotherapy. In addition, chemotherapy could significantly improve the survival in stage II-IV patients and radiotherapy could only improve the survival in stage III patients (all P < 0.01). Marital status, age, grade, tumor size, FIGO stage, surgery, pelvic LNM and chemotherapy were significantly associated with the prognosis of cervical AC.

[on oligozoospermia and asthenospermia].

OBJECTIVE: To observe the clinical effect of Yihechun Capsules (YHC) on oligozoospermia and asthenospermia. METHODS: A total of 181 male patients with infertility were randomly divided into a YHC+Levocarnitine (LC) group (n = 93, including 42 cases of oligozoospermia, 20 cases of asthenospermia and 31 cases of oligoasthenospermia) and an LC control group (n = 88, including 39 cases of oligozoospermia, 22 cases of asthenospermia and 27 cases of oligoasthenospermia), the former treated with YHC (ï¼»0.3 g per capsuleï¼½, once 4 capsules, bid, 30 minutes after meal) combined with LC oral liquid (2－3 g/d, tid, at mealtime) and the latter with LC oral liquid only (2－3 g/d, tid, at mealtime). After 3 months of treatment, comparisons were made between the two groups of patients in sperm concentration, the percentages of grade a and grade a+b sperm, and the rate of pregnancy. RESULTS: Of the 181 patients, 5 in the YHC+LC group and 2 in the LC control group failed to complete the course of treatment. There were no statistically significant differences between the two groups of patients in the baseline sperm concentration and the percentages of grade a and grade a+b sperm (P > 0.05), wich were all markedly increased in both the YHC+LC and the LC control groups (P < 0.05) after 3 months of treatment. And the patients of the YHC+LC group, compared with the controls, showed even more significant increases, as the oligozoospermia patients in sperm concentration (ï¼»21.07 ± 6.98ï¼½ vs ï¼»16.56 ± 1.82ï¼½ ×106/ml, P < 0.05) and the percentages of grade a sperm (ï¼»27.53 ± 3.34ï¼½% vs ï¼»26.88 ± 1.35ï¼½%, P < 0.05) and grade a+b sperm (ï¼»53.32 ± 3.16ï¼½% vs ï¼»52.63 ± 2.48ï¼½%, P < 0.05), the asthenospermia patients in sperm concentration (ï¼»26.36 ± 3.37ï¼½ vs ï¼»24.42 ± 2.21ï¼½ ×106/ml, P < 0.05) and the percentages of grade a sperm (ï¼»25.28 ± 4.64ï¼½% vs ï¼»21.32 ± 3.28ï¼½%, P < 0.05) and grade a+b sperm (ï¼»49.19 ± 2.87ï¼½% vs ï¼»45.64 ± 1.78ï¼½%, P < 0.05), and the oligoasthenospermia patients in sperm concentration (ï¼»19.38 ± 3.39ï¼½ vs ï¼»18.75 ± 1.35ï¼½ ×106/ml, P < 0.05) and the percentages of grade a sperm (ï¼»22.65 ± 4.81ï¼½% vs ï¼»21.31 ± 2.42ï¼½%, P < 0.05) and grade a+b sperm (ï¼»48.74 ± 5.61ï¼½% vs ï¼»44.36 ± 1.32ï¼½%, P < 0.05). The pregnancy rate was dramatically higher in the YHC+LC than in the LC control group (36.4% ï¼»32/88ï¼½ vs 15.1% ï¼»13/86ï¼½, P < 0.01). CONCLUSIONS: Yihechun Capsules combined with Levocarnitine oral liquid is evidently effective for the treatment of oligozoospermia and asthenospermia.

Post-buckling analysis of functionally graded multilayer graphene platelet reinforced composite cylindrical shells under axial compression.

Axially compressed composite cylindrical shells can attain multiple bifurcation points in their post-buckling procedure because of the natural transverse deformation restraint provided by their geometry. In this paper, the post-buckling analysis of functionally graded (FG) multilayer graphene platelets reinforced composite (GPLRC) cylindrical shells under axial compression is carried out to investigate the stability of such shells. Rather than the critical buckling limit, the focus of the present study is to obtain convergence post-buckling response curves of axially compressed FG multilayer GPLRC cylindrical shells. By introducing a unified shell theory, the nonlinear large deflection governing equations for post-buckling of FG multilayer GPLRC cylindrical shells with wide range of thickness are established, which can be easily changed into three widely used shell theories. Load-shortening curves for both symmetric and asymmetric post-buckling modes are obtained by Galerkin's method. Numerical results illustrate that the present solutions agree well with the existing theoretical and experimental data. The effects of geometries and material properties on the post-buckling behaviours of FG multilayer GPLRC cylindrical shells are investigated. The differences in the three shell theories and their scopes are discussed also.

Influence of hepatocyte growth factor-transfected bone marrow-derived mesenchymal stem cells towards renal fibrosis in rats.

Background & objectives: Hepatocyte growth factor (HGF) produced by endothelial cells, fibroblasts, fat cells and other interstitial cells, can promote angiogenesis, repair damaged tissues and resist fibrosis. Mesenchymal stem cells (MSCs) are located in bone marrow and secrete a variety of cytokines and are often used in the repair and regeneration of damaged tissues. This study was aimed to investigate the influence of HGF-transfected bone marrow-derived MSCs towards renal fibrosis in rats. Methods: The HGF gene-carrying adenoviral vector (Ad-HGF) was transfected into MSCs, and the Ad-HGF-modified MSCs were transplanted into rats with unilateral ureteral obstruction (UUO). The localization of renal transplanted cells in the frozen section was observed with fluorescence microscope. The Masson's trichrome staining was performed to observe the renal collagen deposition, and the immunohistochemistry was performed to detect the expressions of α-smooth muscle actin (α-SMA) and HGF in renal tissues. Reverse transcription (RT)-PCR was used to detect the mRNA expressions of α-SMA, HGF and fibronectin (FN). Results: Ad-HGF-modified MSCs could highly express HGF in vitro. On the post-transplantation 3rd, 7th and 14th day, the 4',6-diamidino-2-phenylindole (DAP)-labelled transplanted cells were seen inside renal tissues. Compared with UUO group, the renal collagen deposition in transplantation group was significantly reduced, and the expressions of α-SMA mRNA and protein were significantly decreased, while the expressions of HGF mRNA and protein were significantly increased, and the expression of FN mRNA was significantly decreased (P<0.001). Interpretation & conclusions: Trans-renal artery injection of HGF-modified MSCs can effectively reduce the renal interstitial fibrosis in UUO rat model.

In Situ Capture RT-qPCR: A New Simple and Sensitive Method to Detect Human Norovirus in Oysters.

Human noroviruses (HuNoVs) are the major cause worldwide for non-bacterial acute gastroenteritis. In this study, we applied a novel viral receptor mediated in situ capture RT-qPCR (ISC-RT-qPCR) to detect HuNoVs in oysters and compared with the traditional RT-qPCR method. Ten HuNoVs RT-PCR positive and 5 negative clinical samples from gastroenteritis patients were used to compare specificity and sensitivity of ISC-RT-qPCR against that of the RT-qPCR assay. ISC-RT-qPCR had at a one-log and a two-log increase in sensitivity over that of the RT-qPCR assay for genotype I (GI) and GII, respectively. Distributions of HuNoVs in oyster tissues were investigated in artificially inoculated oysters. GI HuNoVs could be detected in all tissues in inoculated oysters by both ISC-RT-qPCR and RT-qPCR. GII HuNoVs could only be detected in gills and digestive glands by both methods. The number of viral genomic copies (vgc) measured by ISC-RT-qPCR was comparable with RT-qPCR in the detection of GI and GII HuNoVs in inoculated oysters. Thirty-six oyster samples from local market were assayed for HuNoVs by both assays. More HuNoVs could be detected by ISC-RT-qPCR in retail oysters. The detection rates of GI HuNoVs in gills, digestive glands, and residual tissues were 33.3, 25.0, and 19.4% by ISC-RT-qPCR; and 5.6, 11.1, and 11.1% by RT-qPCR, respectively. The detection rates of GII HuNoVs in gills were 2.8% by ISC-RT-qPCR; no GII HuNoV was detected in these oysters by RT-qPCR. Overall, all results demonstrated that ISC-RT-qPCR is a promising method for detecting HuNoVs in oyster samples.

Molecular dynamics simulations of acylpeptide hydrolase bound to chlorpyrifosmethyl oxon and dichlorvos.

Acylpeptide hydrolases (APHs) catalyze the removal of N-acylated amino acids from blocked peptides. Like other prolyloligopeptidase (POP) family members, APHs are believed to be important targets for drug design. To date, the binding pose of organophosphorus (OP) compounds of APH, as well as the different OP compounds binding and inducing conformational changes in two domains, namely, α/ß hydrolase and ß-propeller, remain poorly understood. We report a computational study of APH bound to chlorpyrifosmethyl oxon and dichlorvos. In our docking study, Val471 and Gly368 are important residues for chlorpyrifosmethyl oxon and dichlorvos binding. Molecular dynamics simulations were also performed to explore the conformational changes between the chlorpyrifosmethyl oxon and dichlorvos bound to APH, which indicated that the structural feature of chlorpyrifosmethyl oxon binding in APH permitted partial opening of the ß-propeller fold and allowed the chlorpyrifosmethyl oxon to easily enter the catalytic site. These results may facilitate the design of APH-targeting drugs with improved efficacy.

Nanoscale Ni-B electrocatalyst prepared from nickel ethylenediamine complex for direct ethanol electrocatalytic oxidation.

Ni-B/Cu electrode prepared by the electroless deposition technique of chemical reduction of nickel ethylenediamine complex with BH4- was characterized by SEM, XRD and XPS techniques, respectively, and evaluated using ethanol electrocatalytic oxidation by the method of cyclic voltammetry. The as-prepared Ni-B/Cu electrode exhibited much higher electrocatalytic activity than the Ni-B/Cu electrode obtained via direct reduction of nickel metallic ions. The effects of the nickel ethylenediamine complex can be attributed to both the structural effect and electronic effect. The nickel ethylenediamine complex can not only make an electroless deposition stable and highly dispersed, but also facilitate the formation of more nanoscale microcrystalline Ni on the electrode surface, which increased the electrochemical oxidation activity. Moreover, ethylenediamine influenced the electronic states of Ni and B on the electrode surface, more electrons transfer from the B to Ni that the Ni active sites became more highly unsaturated, which could promote the form of adsorbed active ethanol.

The effect of conformational variability of phosphotriesterase upon N-acyl-L-homoserine lactone and paraoxon binding: insights from molecular dynamics studies.

The organophosphorous hydrolase (PTE) from Brevundimonas diminuta is capable of degrading extremely toxic organophosphorous compounds with a high catalytic turnover and broad substrate specificity. Although the natural substrate for PTE is unknown, its loop remodeling (loop 7-2/H254R) led to the emergence of a homoserine lactonase (HSL) activity that is undetectable in PTE (kcat/km values of up to 2 × 10(4)), with only a minor decrease in PTE paraoxonase activity. In this study, homology modeling and molecular dynamics simulations have been undertaken seeking to explain the reason for the substrate specificity for the wild-type and the loop 7-2/H254R variant. The cavity volume estimated results showed that the active pocket of the variant was almost two fold larger than that of the wild-type (WT) enzyme. pKa calculations for the enzyme (the WT and the variant) showed a significant pKa shift from WT standard values (ΔpKa = 3.5 units) for the His254 residue (in the Arg254 variant). Molecular dynamics simulations indicated that the displacement of loops 6 and 7 over the active site in loop 7-2/H254R variant is useful for N-acyl-L-homoserine lactone (C4-HSL) with a large aliphatic chain to site in the channels easily. Thence the expanding of the active pocket is beneficial to C4-HSL binding and has a little effect on paraoxon binding. Our results provide a new theoretical contribution of loop remodeling to the rapid divergence of new enzyme functions.

[Medical image automatic adjusting window and segmentation].

Image guided surgical navigation system is the most advanced surgical apparatus, which develops most rapidly and has great application prospects in neurosurgery, orthopaedics, E.N.T. department etc. In current surgical navigation systems, windowing, segmenting and registration of medical images all depend on manual operation, and automation of image processing is urgently needed. This paper proposes the algorithm which realizes very well automatic windowing and segmentation of medical images: first, we analyze a lot of MRI and CT images and propose corresponding windowing algorithm according to their common features of intensity distribution. Experiments show that the effects of windowing of most MRI and CT images are optimized. Second, we propose the seed growing algorithm based on intensity connectivity,which can segment tumor and its boundary exactly by simply clicking the mouse, and control dynamically the results in real time. If computer memory permits, the algorithm can segment 3D images directly. Tests show that this function is able to shorten the time of surgical planning, lower the complexity, and improve the efficiency in navigation surgery.

[Determination of 2,6-di-tertbutyl-4-methylphenol in an aviation jet fuel by high performance liquid chromatography].

The content of antioxidant of 2,6-di-tertbutyl-4-methylphenol(BHT) in a new aviation jet fuel (HDF-1) was determined by high performance liquid chromatography. The influences of the volume ratio of methanol and acetate buffer and the flow rate for BHT separation from HDF-1 were studied and the best analysis conditions were obtained. The optimum volume ratio is 85:15 and the optimum flow rate is 1 mL/min. The relation of BHT mass fraction and its peak area has been analyzed and simulated. It was found that they had a good linear relationship.