Hollow-core terahertz Bragg waveguide based on a helical support structure.

A helical structural support scheme is proposed to mechanically support dielectric layers in a hollow-core terahertz Bragg waveguide by means of an axially rotating wrap-around strip structure. The helical-strip supported waveguide samples are fabricated using 3D printing technology, and the waveguide samples are experimentally tested using a terahertz time-domain spectroscopy system. The results show that choosing a suitable helix period can obtain loss characteristics close to those of an ideal Bragg waveguide, with a low transmission loss of less than 0.097 dB/m in the range of 0.57-0.58 THz.

Cascaded terahertz hollow-core Bragg waveguide: numerical design and experimental demonstration.

A THz hollow-core Bragg waveguide with discontinuous support bridges in both radial and axial directions is proposed. The influence of the support bridges on the transmission loss of the waveguide is demonstrated numerically. The proposed waveguide shows confinement loss two orders of magnitude lower than that of the Bragg waveguide with conventional support bridges. A waveguide sample is fabricated by 3D printing technology, and the experimental results show that the transmission loss is in agreement with that of the simulation results. It is also demonstrated that the transmission loss of the fabricated waveguide is mainly determined by the large absorption loss of the waveguide material used in the experiment.

A review of tamoxifen administration regimen optimization for Cre/loxp system in mouse bone study.

Gene knockout is a technique routinely used in basic experimental research, particularly in mouse skeletal and developmental studies. Tamoxifen-induced Cre/loxp system is known for its temporal and spatial precision and commonly utilized by researchers. However, tamoxifen has been shown its side effects on affecting the phenotype of mouse bone directly. This review aimed to optimize tamoxifen administration regimens including its dosage and duration, to identify an optimal induction strategy that minimizes potential side effects while maintaining recombination efficacy. This study will help researchers in designing gene knockout experiments in bone when using tamoxifen.

Prognostic Factors and the Role of Adjuvant Chemotherapy in Pathological Node-Negative T3 Gastric Cancer.

The role of adjuvant chemotherapy in pathological T3N0M0 (pT3N0M0) gastric cancer (GC) remains unclear. The aim of this study was to analyze the prognostic factors of patients with pT3N0M0 GC and to clarify which ones could benefit from adjuvant chemotherapy. A total of 137 patients with pT3N0M0 GC were recruited between 1994 and 2020. Clinicopathological factors and adjuvant chemotherapy regimens were retrospectively collected. Prognostic factors of disease-free survival (DFS) and cancer-specific survival (CSS) were determined using univariate and multivariate analyses. The chemotherapy group was younger (p = 0.012), had had more lymph nodes retrieved (p = 0.042) and had higher percentages of vascular invasion (p = 0.021) or perineural invasion (p = 0.030) than the non-chemotherapy group. There were no significant differences in DFS (p = 0.222) and CSS (p = 0.126) between patients treated with or without adjuvant chemotherapy. Stump cancer, tumor size and perineural invasion were associated with higher rates of recurrence. Tumor size was an independent prognostic factor for DFS (hazard ratio, 4.55; confidence interval, 1.59-12.99; p = 0.005) and CSS (hazard ratio, 3.97; confidence interval, 1.38-11.43; p = 0.011). Tumor size independently influenced survival outcomes in pT3N0M0 patients who underwent radical surgery with and without adjuvant chemotherapy.

Risk factors of recurrent secondary hyperparathyroidism after adequate primary surgical treatment.

Background: Secondary hyperparathyroidism (SHPT) is a common condition in patients with end-stage renal disease (ESRD) who are on dialysis. Parathyroidectomy is a treatment for patients when medical therapy has failed. Recurrence may occur and is indicated for further surgery in the era of improved quality of care for ESRD patients. Methods: We identified, 1060 patients undergoing parathyroidectomy from January, 2011 to June, 2020. After excluding patients without regular check-up at our institute, primary hyperparathyroidism, or malignancy, 504 patients were enrolled. Sixty-two patients (12.3%, 62/504) were then excluded due to persistent SHPT even after the first parathyroidectomy. We aimed to identify risk factors for recurrent SHPT after the first surgery. Results: During the study period, 20% of patients who underwent parathyroidectomy at our institute (in, 2019) was due to recurrence after a previous parathyroidectomy. There were 442 patients eligible for analysis of recurrence after excluding patients with the persistent disease (n = 62). While 44 patients (9.95%) had recurrence, 398 patients did not. Significant risk factors for recurrent SHPT within 5 years after the first parathyroidectomy, including dialysis start time to first operation time < 3 years (p = 0.046), postoperative PTH >106.5 pg/mL (p < 0.001), and postoperative phosphorus> 5.9 mg/dL (p = 0.016), were identified by multivariate analysis. Conclusions: The starting time of dialysis to first operation time < 3 years in the patients with dialysis, postoperative PTH> 106.5 pg/mL, and postoperative phosphorus> 5.9 mg/dL tended to have a higher risk for recurrent SHPT within 5 years after primary treatment.

Optimal Timing of Cholecystectomy for Patients with Concurrent Acute Cholecystitis and Acute Cholangitis after Successful Biliary Drainage by Interventional Endoscopic Retrograde Cholangiopancreatography.

Background: Concurrent acute cholecystitis and acute cholangitis is a unique clinical situation. We tried to investigate the optimal timing of cholecystectomy after adequate biliary drainage under this condition. Methods: From January 2012 to November 2017, we retrospectively screened all in-hospitalized patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and then identified patients with concurrent acute cholecystitis and acute cholangitis from the cohort. The selected patients were stratified into two groups: one-stage intervention (OSI) group (intended laparoscopic cholecystectomy at the same hospitalization) vs. two-stage intervention (TSI) group (interval intended laparoscopic cholecystectomy). Interrogated outcomes included recurrent biliary events, length of hospitalization, and surgical outcomes. Results: There were 147 patients ultimately enrolled for analysis (OSI vs. TSI, 96 vs. 51). Regarding surgical outcomes, there was no significant difference between the OSI group and TSI group, including intraoperative blood transfusion (1.0% vs. 2.0%, p = 1.000), conversion to open procedure (3.1% vs. 7.8%, p = 0.236), postoperative complication (6.3% vs. 11.8%, p = 0.342), operation time (118.0 min vs. 125.8 min, p = 0.869), and postoperative days until discharge (3.37 days vs. 4.02 days, p = 0.643). In the RBE analysis, the OSI group presented a significantly lower incidence of overall RBE (5.2% vs. 41.2%, p < 0.001) than the TSI group. Conclusions: Patients with an initial diagnosis of concurrent acute cholecystitis and cholangitis undergoing cholecystectomy after ERCP drainage during the same hospitalization period may receive some benefit in terms of clinical outcomes.

Phenethoxy Derivatives with Anti-inflammatory Activities from the Betelnut Endophytic Trichoderma asperellum G10.

Eight new phenethoxy derivatives, trichoasperellins A-H (1-8), were isolated from the endophytic fungus Trichoderma asperellum G10 isolated from the medicinal plant Areca catechu L. The structures of these compounds were elucidated from spectroscopic data, J-based configurational analysis, and Mosher's methods. Compounds 1-4 and 6-8 bear one or two multioxidized C7 moieties with the same carbon skeleton. The carbon skeletons of compounds 6-8 are new, all containing three moieties connected via two acetal carbons similar to those of disaccharide glycosides. Compound 4 inhibited nitric oxide production with an IC50 value of 48.3 µM, comparable to that of the positive control indomethacin (IC50, 42.3 µM).

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Given its high root regeneration ability and adaptation capacity, Spartina alterniflora would predominate the resource competition with other plant species. As an invasive alien species, it has caused serious damages to the coastal ecosystem of China. We explored the impacts of S. alterniflora invasion on the growth and expansion of mangroves around the coastal zones around Guangxi Shankou Mangrove National Nature Reserve (GSMNNR). The area of S. alterniflora and mangroves in the GSMNNR was analyzed based on a sequence of Landsat satellite multispectral images collected during 1995 to 2019. The results showed that S. alterniflora predominated in the competition with mangroves without human intervention. The area of S. alterniflora decreased under the conditions of cutting, rooting and other management measures, while the average annual growth rate of mangrove area correspondingly increased. It indicated that the invasion of S. alterniflora would inhibit the growth and expansion of mangroves. The S. alterniflora management measures, such as mowing and rooting, could weaken the negative impacts of S. alterniflora on mangroves. Mangroves could thus be effectively protected. This study could provide quantitative scientific data for S. alterniflora management and the protection of the mangrove ecosystem in the GSMNNR, and thus be a valuable reference to the prevention on a larger scale of S. alterniflora and the formulation of further protective measures for mangroves.

Optimal Perioperative Nutrition Therapy for Patients Undergoing Pancreaticoduodenectomy: A Systematic Review with a Component Network Meta-Analysis.

Numerous strategies for perioperative nutrition therapy for patients undergoing pancreaticoduodenectomy (PD) have been proposed. This systematic review aimed to summarize the current relevant published randomized controlled trials (RCTs) evaluating different nutritional interventions via a traditional network meta-analysis (NMA) and component network meta-analysis (cNMA). EMBASE, MEDLINE, the Cochrane Library, and ClinicalTrials.gov were searched to identify the RCTs. The evaluated nutritional interventions comprised standard postoperative enteral nutrition by feeding tube (Postop-SEN), preoperative enteral feeding (Preop-EN), postoperative immunonutrients (Postop-IM), preoperative oral immunonutrient supplement (Preop-IM), and postoperative total parenteral nutrition (TPN). The primary outcomes were general, infectious, and noninfectious complications; postoperative pancreatic fistula (POPF); and delayed gastric emptying (DGE). The secondary outcomes were mortality and length of hospital stay (LOS). The NMA and cNMA were conducted with a frequentist approach. The results are presented as odds ratios (ORs) and 95% confidence intervals (CIs). Two primary outcomes, infectious complications and POPF, were positively influenced by nutritional interventions. Preop-EN plus Postop-SEN (OR 0.11; 95% CI 0.02~0.72), Preop-IM (OR 0.22; 95% CI 0.08~0.62), and Preop-IM plus Postop-IM (OR 0.11; 95% CI 0.03~0.37) were all demonstrated to be associated with a decrease in infectious complications. Postop-TPN (OR 0.37; 95% CI 0.19~0.71) and Preop-IM plus Postop-IM (OR 0.21; 95% CI 0.06~0.77) were clinically beneficial for the prevention of POPF. While enteral feeding and TPN may decrease infectious complications and POPF, respectively, Preop-IM plus Postop-IM may provide the best clinical benefit for patients undergoing PD, as this approach decreases the incidence of both the aforementioned adverse effects.

Metabolism of Proteins and Amino Acids in Critical Illness: From Physiological Alterations to Relevant Clinical Practice.

The clinical impact of nutrition therapy in critically ill patients has been known for years, and relevant guidelines regarding nutrition therapy have emphasized the importance of proteins. During critical illness, such as sepsis or the state following major surgery, major trauma, or major burn injury, patients suffer from a high degree of stress/inflammation, and during this time, metabolism deviates from homeostasis. The increased degradation of endogenous proteins in response to stress hormones is among the most important events in the acute phase of critical illness. Currently published evidence suggests that adequate protein supplementation might improve the clinical outcomes of critically ill patients. The role of sufficient protein supplementation may even surpass that of caloric supplementation. In this review, we focus on relevant physiological alterations in critical illness, the effects of critical illness on protein metabolism, nutrition therapy in clinical practice, and the function of specific amino acids.

Impact of the highest amylase level in drain fluid on surgical outcomes and postoperative interventions in patients undergoing pancreaticoduodenectomy.

OBJECTIVES: The clinical significance of the highest drain fluid amylase (DFA) level beyond pancreaticoduodenectomy (PD) postoperative day three (POD 3) remains unclear. This study investigated the impact of highest DFA level beyond POD 3 on postoperative pancreatic fistula (POPF) severity and outcomes of patients undergoing PD with POPF. METHODS: Patient demographics of biochemical POPF and clinically relevant POPF (CR-POPF) were compared. Predictive factors were assessed using binary logistic regression. Receiver operating characteristic curve analysis was performed to determine the optimal cutoff value of highest DFA (beyond POD 3). We compared length of hospital stay, surgical mortality rates, and need for postoperative interventions by highest DFA level. RESULTS: Patients with CR-POPF had an older age (p = 0.039), required intraoperative blood transfusion (p = 0.006), and had greater highest DFA levels (p = 0.001) than those with biochemical POPF. The optimal highest DFA cutoff was 2014.5 U/L. Multivariate analysis showed that percentage of patients with intraoperative blood transfusion (p = 0.011; odds ratio, 3.716) and a highest DFA > 2014.5 U/L beyond POD 3 (p = 0.001; odds ratio, 5.722) was predictive of CR-POPF. CONCLUSION: Highest DFA > 2014.5 U/L beyond POD 3 is an independent predictor for CR-POPF. At a highest DFA >2014.5 U/L, 30-day surgical mortality rate, length of stay, and need for postoperative interventions did not differ.

Alternative application of percutaneous cholecystostomy in patients with biliary obstruction.

PURPOSE: Percutaneous cholecystostomy (PC) is an important modality for acute cholecystitis and has been applied for other clinical scenarios as well. In the present study, we aimed to investigate an alternative use of PC for obstructive jaundice. METHODS: From January 2012 to December 2018, eligible subjects were selected from patients undergoing PC in our institute. The characteristics, spectrum of underlying disease, indication for PC performance, details of the procedure, and treatment effect were all investigated. RESULTS: During the study period, 1364 patients underwent PC. Seventy patients fulfilled the defined inclusion criteria. While 47 patients were diagnosed with malignant biliary obstruction with or without cholangitis, 23 patients were diagnosed with nonmalignant biliary obstruction and acute cholangitis. There were 63 patients (90%) diagnosed with acute cholangitis. Pancreatic cancer (n = 24, 51%) and advanced malignancy (n = 28, 59%) were noted mostly in the group with malignant biliary obstruction. Treatment effects were proven by laboratory data, including the white blood cell count, C-reactive protein level, and hepatic function. CONCLUSION: PC can temporize definitive therapies and serve as an alternative treatment for patients with nonmalignant conditions. For patients with advanced malignancy, PC can serve as a palliative procedure that has a high success rate and low complication rate and effectively relieves biliary obstruction.

Two new indole-diterpenoids from the marine-derived fungus Penicillium sp. KFD28.

Two new compounds named epipaxilline (1) and penerpene J (2) were isolated from the marine-derived fungus Penicillium sp. KFD28. Their structures including absolute configurations were determined on the basis of spectroscopic methods and ECD analysis. Compounds 1 and 2 showed inhibitory activities against PTP1B with IC50 values of 31.5 and 9.5 µM, respectively, and compound 2 also showed inhibitory activities against TCPTP with IC50 value of 14.7 µM.

Surgical options for submucosal tumors near the esophagogastric junction: does size or location matter?

BACKGROUND: Submucosal tumors (SMTs) of different etiologies exist from esophagus to rectum. Esophagogastric junction (EGJ) is one of the known difficult locations for tumor resection. Although minimally invasive surgery (MIS) is a well-established approach for gastrointestinal surgery, there is no consensus that MIS for resection of SMTs around EGJ is superior to laparotomy. We tried to clarify the factors that determine the surgeons' choices between these two approaches. METHODS: From January 2002 to June 2016, 909 patients with SMTs underwent resection in our department. Among them, 119 patients (13%) had SMTs around EGJ were enrolled by retrospective review. The clinicopathological features and tumor-related parameters were reviewed and analyzed. RESULTS: The cohort was stratified into three groups according to the extent of gastrectomy and surgical approaches. The three groups are as following: major gastrectomy (n = 13), minor gastrectomy by laparotomy (n = 51), and minor gastrectomy with MIS (n = 55). The average tumor size was significantly larger in the major gastrectomy group than in the two minor gastrectomy groups; however, there was no difference between the two minor gastrectomy groups (5.33 cm, 4.07 cm, and 3.69 cm, respectively). The minor gastrectomy with MIS required least hospital stay and operation duration also. We re-stratify the two minor gastrectomy groups (n = 106) according to the orientation of SMTs around the EGJ into 4 zones. Most of SMTs located on the greater curvature side of the EGJ were resected with MIS (82% versus 18%), whereas SMTs in the other zones were resected more often by laparotomy (59% versus 41%). There was no surgical mortality within the cohort, while minor gastrectomy with MIS yielded least number of leakages among the three groups. CONCLUSIONS: For SMTs around the EGJ, larger tumors (diameter of more than 5 cm) are more likely to be resected with major gastrectomy. To resect SMTs around the EGJ in a wedge-like (minor gastrectomy) fashion, tumors located other than the greater curvature side were more often resected by laparotomy. However, MIS yielded acceptable safety and surgical outcomes compared to conventional laparotomy for SMTs around the EGJ of the same size.

Modification and Compounding of CaMgAl-Layered Double Hydroxides and Their Application in the Flame Retardance of Acrylonitrile-Butadiene-Styrene Resin.

CaMgAl-layered double hydroxides (CaMgAl-LDHs) were synthesized by a co-precipitation method to prepare sodium oleate-modified, borate-intercalated CaMgAl-LDHs (O-CaMgAl-LDHs) using in-situ intercalation and modification, and the LDHs samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), and thermal gravimetric analysis (TGA). The FESEM observations showed that the as-prepared CaMgAl-LDHs had a lamellar structure with a particle size of 200~500 nm, while the O-CaMgAl-LDHs had a plate-like structure with a particle size of about 100 nm. TGA showed that O-CaMgAl-LDHs resulted in higher thermal stability at high temperature compared to CaMgAl-LDHs. O-CaMgAl-LDHs/ABS composites were prepared by adding O-CaMgAl-LDHs to acrylonitrile-butadiene-styrene resin (ABS) to test the resulting flame retardancy and mechanical properties, and the results showed that the limiting oxygen index (LOI) could increase from 18% to 26%, while the mechanical properties decreased significantly when the added fraction was 40% (relative to ABS). O-CaMgAl-LDHs, ammonium polyphosphate (APP) and expandable graphite (EG) were added into the ABS to prepare ABS composites, and the effects of different compositions on the flame retardancy and mechanical properties of the ABS composites were investigated. The results showed that, when adding 5 g of O-CaMgAl-LDHs, 1 g of APP, and 14 g of EG into 40 g of ABS, the LOI of the ABS composite reached 28.8%, and the composite prepared could meet the V-0 grade requirements of the UL-94 combustion test, while the flexural strength decreased only 21.9% compared to pure ABS, the smallest decrease compared to all of the other composites.

Charge-Transfer-Promoted High Oxygen Evolution Activity of Co@Co9S8 Core-Shell Nanochains.

Co@Co9S8 nanochains with core-shell structures are prepared by a direct-current arc-discharge technique and followed sulfurization at 200 °C. The nanochains, which consist of uniform nanospheres connecting each other, can range up to several micrometers. The thickness of Co9S8 shell can be changed by regulating the sulfurization time. In this heterostructure of Co@Co9S8, Co nanochains function as a conductive network and can inject electrons into Co9S8, which manipulates the work function of Co9S8 and makes it more apposite for catalysis. The density functional theory calculation also reveals that coupling with Co can significantly reduce the overpotential needed to drive the oxygen evolution process. On the basis of the exclusive structure, Co@Co9S8 nanochains have shown high catalytic activity in the oxygen evolution reaction. Co@Co9S8 reaches an overpotential of 285 mv at 10 mA cm-2, which is much lower than that of Co nanochains (408 mV) and Co9S8 (418 mV). Co@Co9S8 also shows higher catalytic activity and robustness compared to state-of-the-art noble-metal catalyst RuO2.

Transdermal Delivery of Luteinizing Hormone-releasing Hormone with Chitosan Microneedles: A Promising Tool for Androgen Deprivation Therapy.

Long-term administration of luteinizing hormone-releasing hormone analogs (LHRHa) is the main type of androgen-deprivation therapy (ADT) for lethal prostate cancer. A fully insertable microneedle system, composed of embeddable chitosan microneedles and a dissolvable polyvinyl alcohol/polyvinyl pyrrolidone supporting array, was developed for sustained delivery of LHRHa to the skin. A porcine cadaver skin test showed that chitosan microneedles can be fully embedded within the skin and microneedle-created micropores reseal within 7 days. The measured LHRHa loading amount was 73.3±2.8 µg per microneedle patch. After applying goserelin-containing microneedles to mice, serum LH levels increased initially and then declined below baseline at day 7. In contrast, serum testosterone levels increased to reach a peak at day 14 and then declined to a castration level at day 21. Additionally, such a castration level was maintained for 2 weeks. Therefore, transdermal delivery of goserelin with embeddable chitosan microneedles can produce a castrated state in mice. Such a system is a promising, feasible means of delivering ADT.

High-order mode conversion based on adiabatical mode evolution for mode division multiplexing applications.

Mode conversion based on adiabatical mode evolution in a two-core configuration is investigated. The configuration can convert all the launching modes to higher-order modes from one port and convert all the launching modes to lower-order modes from another port. Mode conversion between the two degenerated high-order modes is also demonstrated numerically. The mode conversion feature is only dependent on the relationship between the effective mode indices of the two cores in the configuration, which shows the characteristics of high flexibility and large fabrication tolerance.

Efficacy of External Beam Radiation-Based Treatment plus Locoregional Therapy for Hepatocellular Carcinoma Associated with Portal Vein Tumor Thrombosis.

Background. Portal vein tumor thrombosis (PVTT) is a common event in advanced hepatocellular carcinoma (HCC). The optimal treatment for these patients remains controversial. Methods. A retrospective review of 149 patients who had unresectable HCC associated with PVTT between January 2005 and December 2012 was performed. Outcomes related to external beam radiation-based treatment were measured, and clinicopathological features and parameters affecting prognosis were analyzed as well. Results. The radiotherapeutic response of PVTT was an important element that affected the overall treatment response of HCC. Serum α-fetoprotein < 400 ng/mL, the presence of a radiotherapeutic response on PVTT, and receiving additional locoregional therapy were significant prognostic factors affecting the survival of patients. Patients who had received additional locoregional therapy obtained a better outcome, and six of them were eventually able to undergo surgical management with curative intent. Conclusion. The outcome of HCC associated with PVTT remains pessimistic. In addition to the current recommended treatment using sorafenib, a combination of external beam radiotherapy targeting PVTT and locoregional therapy for intrahepatic HCC might be a promising strategy for patients who had unresectable HCC with PVTT. This approach could perhaps offer patients a favorable outcome as well as a possible cure with following surgical management.