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Background: Transanal total mesorectal excision has emerged as a potential solution to certain limitations associated with laparoscopic total mesorectal excision in rectal cancer patients. Differences in surgical approaches have raised questions regarding their impact on the risk of postoperative urinary retention, with limited data available from large scale randomized clinical study. Objective: To report incidence of postoperative urinary retention and evaluate the associated risk factors for transanal total mesorectal excision. Design: In this randomized controlled trial (ClinicalTrials. gov NCT06147492), we retrieved 524 patients who received total mesorectal excision (TME) for stage I–III rectal cancer between June 2019 and April 2022, and the patients were randomly assigned in a 1:1 ratio to undergo either taTME or laTME. Patients: We enrolled 524 patients who underwent total mesorectal excision for stage I–III rectal cancer between June 2019 and April 2022. Main outcome measures: The incidence of postoperative urinary retention. Results: Among the 524 enrolled patients, 261 were randomized to the laTME group, while 263 were were randomized the taTME group. The median age was 58 years, and 340 participants (64.8 %) were male. Notably, 37 individuals (7.0 %) experienced postoperative urinary retention during the follow-up period, with no significant disparity was observed between the taTME and laTME groups (6.8 % and 7.2 %, respectively, P = 0.98). Risk factors associated with PUR in patients following taTME encompassed early removal of the urinary catheter (P = 0.006), net infusion rate >4.09 ml kg−1.h−1 (P = 0.006), and an age surpassing 65 years (P = 0.0321). Limitations: The generalizability of the findings outside specialist rectal cancer centers may be limited. Conclusions: Transanal total mesorectal excision was not found to heighten the risk of postoperative urinary retention. Nonetheless, it is advisable removing postoperative catheter beyond the initial day and exercising caution in the administration of intravenous fluids in clinical practice for taTME procedures.

Purpose: Malignant biliary obstruction (MBO) is common in patients with advanced malignant tumors, leading to poor prognosis and hindering antitumor therapy. The purpose of our study was to assess the survival outcomes for patients under therapy after percutaneous transhepatic biliary drainage (PTBD) and identify prognostic factors associated with survival in patients with MBO. Methods: From July 2010 to February 2021, 269 patients with MBO secondary to malignant tumor were divided into two groups (functional success and non-functional success). Survival time and prognostic factors were analyzed by Kaplan–Meier curves and the Cox model. Results: The overall median survival time after PTBD was 4.6 months (95 % IC:3.9–5.3). The 3- and 6-month survival rates were 68.0 % and 38.7 %, respectively. The median survival improved from 3.2 months to 8.4 months when the procedure achieved functional success. Multivariate analysis demonstrated that functionally successful drainage and antitumor treatment after PTBD were independent positive prognostic factors, but the total bilirubin after drainage and tumor size were independent negative predictive values. Conclusions: Functionally successful drainage could prolong survival time in patients with malignant biliary obstruction. Palliative care after drainage can prolong patient survival and improve their quality of life.

Thanks to their thermal stability, resistance to oxidation and mechanical strength, cobalt-chrome molybdenum alloys are considered an ideal alloy for high temperature applications. The surface oxide layer evolves as a function of time and temperature, changing its chemical structure and increasing its thickness from a few nanometers to various microns. Making use of various diffractographic and spectroscopic techniques, namely X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and glow-discharge optical emission spectroscopy, coupled with complementary analysis, this work gives new insights on the chemical bonding, crystallographic structure, thickness and elemental composition of the oxide layers as a function of both time and temperature of oxidation. Results show that the initial nanometric passive layer of Co3O4 evolves into a metastable, sub-micrometric CoCrO4 structure and finally stabilizes into a micrometric Cr2O3 at the highest temperatures. This paper fills a fundamental gap in the understanding of the chemistry and stability of Cobalt-based alloys used for high temperature applications, such as in poppet or exhaust valves, aerospace components or hot gas turbines. Once calibrated, this innovative, complete surface characterization approach can be ideally extended to other metallic alloys.

While joint arthroplasty remains nowadays the most popular option available to repair chronically degenerated osteoarthritic joints, possibilities are recently emerging for regeneration of damaged cartilage rather than its replacement with artificial biomaterials. This latter strategy could allow avoiding the quite intrusive surgical procedures associated with total joint replacement. Building upon this notion, we first apply Raman spectroscopy to characterize diseased cartilage in a mice model of instability-induced knee osteoarthritis (OA) upon medial collateral ligament (MCL) and medial meniscus (MM) transections. Then, we examine the same OA model after cartilage regeneration by means of messenger RNA (mRNA) delivery of a cartilage-anabolic runt-related transcription factor 1 (RUNX1). Raman spectroscopy is shown to substantiate at the molecular scale the therapeutic effect of the Runx1 mRNA cartilage regeneration approach. This study demonstrates how the Raman spectroscopic method could support and accelerate the development of new therapies for cartilage diseases.

Following the rising interested on 3D-printing technologies, this research explores the possibility to apply nitride-polymethylmethacrylate composite coatings on 3D printed parts in order to increase their resistance to bacteria colonization. Four different nitrides were tested: silicon, zirconium, hafnium and aluminum. Trans-micrometric particles of hafnium nitride (average size 1 µm) could be dispersed better than the other three nitrides (average size between 8 and 10 µm), but the chemical analysis confirmed that the former, due to the higher surface area, are more prone to spontaneous oxidation in air. After deposition, the surface of the various coatings contained between 40% (silicon nitride) and 90% (hafnium nitride) of exposed ceramic particles. All composite materials showed antibacterial effects when compared to standard polymethylmethacrylate, with hafnium nitride being the most effective against E. coli and aluminum nitride against S. epidermidis. It has been postulated that while Si3N4 long-term antibacterial effects are granted by the constant dissolution of the SiO2 surface layer, zirconium and hafnium composites are effective because they possess antibacterial properties both in their nitride and oxide forms.

The effect of crystal size of HMOR from micro size to 50 nm, with the apparent similar acid site density, on catalytic performance for the dimethyl ether (DME) carbonylation was investigated. The crystal size of HMOR is sensitive to the deactivation rate of DME carbonylation reaction, and the higher stability around 200 nm can be achieved. The characterization studies reveal that the diffusions of MA product play a key role during the induction and deactivation period in DME carbonylation. These will be helpful for guiding the large-scale synthesis of mordenite zeolites catalysts with high efficiencies for DME carbonylation.

In vitro and in vivo studies have recently shown that silicon nitride (Si3N4) is an osseoconductive and potential osseoinductive biomaterial. Even though the amount of bone mineral produced by Si3N4 was inferior when compared to commercial Bioglass®, it strongly stimulated the production of extracellular matrix and collagen tissues. Consequently, this study was designed to determine if appropriate mixtures of Bioglass® and Si3N4 might improve the ratio of mineral apatite to its biological matrix. Commercial 45S5 Bioglass® powder was mixed with 5 and 10 mol% Si3N4 powder, followed by melting, cooling, crushing, and comminution. The composite powders had modified morphologies and chemical structures including a reduced average particle size, a reduction of oxygen in the SiO backbone structure, and trapped CO2 gas which was converted into calcium carbonate. When exposed to human osteosarcoma cells within an osteogenic medium, the 5 mol% Si3N4 composite powder resulted in higher amounts of hydroxyapatite while the 10 mol% Si3N4 powder provided in a more balanced combination of collagen and mineral fractions closer to the natural composition of native human bone. Keywords: Bioglass, Si3N4, Osteosarcoma, Nitrogen, Spectroscopy, Osseointegration

Background: Currently, hepatocellular carcinoma (HCC) patients with refractory ascites (RA) have a very poor prognosis, and there are no effective treatments recommended by the guidelines. A treatment strategy that utilizes a transjugular intrahepatic portosystemic shunt (TIPS) combined with subsequent antitumor treatment is explored in this study for its feasibility and clinical value. Methods: One month after TIPS, the ascites grade and Child-Pugh scores and stages were reassessed to compare changes in the preoperative indicators. Results: A total of 68 patients from 3 centers were enrolled. After TIPS, the following results were obtained: a complete response (CR), partial response (PR), or absent RA response (AR) of 38 [55.9%], 21 [30.9%], and 9 [13.2%], respectively. The control of RA was 86.8%. The median Child–Pugh scores prior to TIPS and one month after TIPS were 8 (IQR 7–9) and 7 (IQR 6–8), respectively. The down, unchanged, and elevated Child–Pugh stages were 26 [38.2%], 36 [53.0%], and 6 [8.8%], respectively. The postoperative Child–Pugh scores were significantly lower than the preoperative (p

Zirconia is the most common ceramic used in dental implants. Even if it possesses both mechanical strength and esthetics, its intrinsic bio-inertness often results in a lack of biological integration. On the other hand, Si3N4 has been proved to be bio-active and to be able to easily osteointegrate. In this work, a Si3N4 powder-based laser-cladding process has been developed in order to improve the biological response to biomedical zirconia. The process resulted in the formation of a composite coating with Si3N4 particles dispersed in nano-crystalline/amorphous silicon. Microscopic observation showed that the layer is adherent to the substrate. The application of the laser cladding treatment resulted in an increase of the roughness, further enhancing the probability of interaction with biological tissues and consequently the bioactivity. Testing with human osteosarcoma cell lines resulted in the formation of bone tissue with high collagen maturity, high carbonate to phosphate ratios and good tissue mineralization, but lower cell proliferation when compared to stoichiometric Si3N4. The bone tissue quality parameters, as measured by Raman spectroscopy, resulted to be comparable to healthy human bone tissue and suggest that laser-cladded Si3N4 treatments might be able to improve the stability of zirconia implants.

Summary: Differentiation of human pluripotent stem cells (hPSCs) into striatal medium spiny neurons (MSNs) promises a cell-based therapy for Huntington's disease. However, clinical-grade MSNs remain unavailable. Here, we developed a chemical recipe named XLSBA to generate clinical-grade MSNs from embryonic stem cells (ESCs). We introduced the γ-secretase inhibitor DAPT into the recipe to accelerate neural differentiation, and replaced protein components with small molecules. Using this optimized protocol we could efficiently direct regular human ESCs (hESCs) as well as clinical-grade hESCs to lateral ganglionic eminence (LGE)-like progenitors and striatal MSNs within less than half of the time than previous protocols (within 14 days and 21 days, respectively). These striatal cells expressed appropriate MSN markers and electrophysiologically acted like authentic MSNs. Upon transplantation into brains of neonatal mice or mouse model of Huntington's disease, they exhibited sufficient safety and reasonable efficacy. Therefore, this quick and highly efficient derivation of MSNs offers unprecedented access to clinical application. : In this article, Wu and colleagues showed that a cocktail of small molecules could induce clinical-grade hESCs into clinically compatible striatal LGE-like progenitors and GABAergic MSNs rapidly and efficiently. Keywords: clinical-grade hESCs, differentiation, striatal medium spiny neurons, small molecules

The surfaces of silicon nitride (β-Si3N4) and zirconia toughened alumina (ZTA) were patterned using a high-energy laser source, which operated at a wavelength of 1064 nm. The patterning procedure yielded a series regular, cylindrical cavities 500 and 300 μm in diameter and depth, respectively. These cavities were subsequently filled with bioglass mixed with different fractions of Si3N4 powder (0, 5, and 10 mol.%) to obtain bioactive functionalized bioceramic surfaces. The laser-patterned samples were first characterized using several spectroscopic techniques before and after functionalization, and then tested in vitro with respect to their osteoconductivity using a human osteosarcoma cell line (SaOS-2). After in vitro testing, fluorescence microscopy was used to address the biological response and to estimate osteopontin and osteocalcin protein contents and distributions. The presence of bioglass greatly enhanced the biological response of both ceramic surfaces, but mainly induced production of inorganic apatite. On the other hand, the addition of minor fraction of Si3N4 into the bioglass-filled holes greatly enhanced bio-mineralization and stimulated the SaOS-2 cells to produce higher amounts of bone extracellular matrix (collagen and proteins), thus enhancing the osteopontin to osteocalcin ratio. It was also observed that the presence of a fraction of Si3N4 in the powder mixture filling the holes bestowed more uniform cell colonization on the otherwise bioinert ZTA surface.

In this study, we monitored the effect of Al 3+ ions on mesenchymal cells (KUSA-A1) and human fibroblasts (NHDF) by means of in vitro experiments by culturing the cells with addition of small concentrations of aluminum ions (i.e., 0.1, 1, 10, and 100 ppm). Bone formation test was then conducted using KUSA-A1. Small concentrations of aluminum ions delayed but did not completely inhibit cell proliferation. The amount of bone tissue decreased as the concentration of Al 3+ increased and crystallinity changes were also detected by Raman spectroscopic experiments. Moreover, Al 3+ ions greatly affected both structure and chemistry of bone tissues with mineral nodules becoming larger and atomic substitution of Ca with Al in bone tissue being more preponderant with increasing Al 3+ concentration. Such effects in turn impaired the balance between mineral and collagen in the formed bone tissue., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The literature on tribological assessments of artificial hip joints usually focuses on correlations between joint composition, size, and specific wear rates, but conspicuously ignores the physical aspects behind the occurrence of degradation mechanisms of friction and wear. Surface degradation in artificial joints occurs because of increases in temperature and local exacerbation of contact stresses inside the moving contact as a consequence of physical and chemical modifications of the sliding surfaces. This article reports about the development of a new pin-on-ball spectroscopy-assisted tribometer device that enables investigating also physical rather than merely engineering aspects of wear processes using in situ Raman and fluorescence techniques. This innovative tribometer is designed to bring about, in addition to conventional tribological parameters, also information of temperature, stress and phase transformations in the femoral heads as received from the manufacturer. Raman and fluorescence spectra at the point of sliding contact are recorded durilng reciprocating hard-on-hard dry-sliding tests. Preliminary results were collected on two different commercially available ceramic-on-ceramic hip joint bearing couples, made of monolithic alumina and alumina-zirconia composites. Although the composite couple showed direct evidence of tetragonal-to-monoclinic phase transformation, which enhanced the coefficient of friction, the specific wear rate was significantly lower than that of the monolithic one (i.e., by a factor 2.63 and 4.48 on the pin and head side, respectively). In situ collected data compared to ex situ analyses elucidated the surface degradation processes and clarified the origin for the higher wear resistance of the composite as compared to the monolithic couple., (Copyright © 2013 Elsevier Ltd. All rights reserved.)