Depolymerization and Re/Upcycling of Biodegradable PLA Plastics.

With the escalating utilization of plastic products, global attention has been increasingly drawn to environmental pollution and recycling challenges stemming from plastic waste. Against this backdrop, biodegradable plastics have emerged as viable alternatives owing to their sustainability and capacity for biodegradation. Polylactic acid (PLA) presently commands the largest market share among biodegradable plastics, finding extensive application in products such as thin films, medical materials, and biodegradable straws. However, the widespread adoption of PLA is hindered by challenges such as high cost, low recycling rates, and complete degradation to H2O and CO2 in natural conditions. Therefore, it is imperative and time-sensitive to explore solutions for the depolymerization and re/upcycling of PLA waste plastics. This review comprehensively outlines the current landscape of PLA recycling methods, emphasizing the advantages and significance of chemical re/upcycling. The subsequent exploration encompasses recent breakthroughs and technical obstacles inherent in diverse chemical depolymerization methods. Ultimately, this review accentuates the impediments and forthcoming possibilities in the realm of PLA plastics, emphasizing the pursuit of closed-loop recycling and upcycling.

Subcutaneous implantation of nodular goiter after transoral endoscopic thyroidectomy vestibular approach: A case study and review of literature.

BACKGROUND: Extrathyroid implantation or dissemination of thyroid tissue secondary to a thyroid procedure is rare. Most of these belonged to thyroid carcinoma with metastatic potential and uncommon for benign pathologies. METHODS: We report the case of a 31-year-old female who was identified to have multiple subcutaneous implantation of thyroid tissue 5 years after transoral endoscopic thyroidectomy vestibular approach. A comprehensive literature search on implantation of thyroid tissue secondary to thyroid procedures was performed. RESULTS: Accidental tearing of the capsule during previous surgery may lead to the subcutaneous implantation. Through literature review, a total 29 articles with 47 patients were identified. 33.3% were benign lesions, and implantation was mostly secondary to fine needle aspiration biopsy (46.5%). CONCLUSIONS: Subcutaneous or port site implantation after endoscopic thyroid surgery may occur in benign thyroid pathologies and therefore, oncologic principles must be strictly followed during surgery regardless of its histopathological nature.

The identification and functional analysis of CircRNAs in endometrial receptivity of mice with polycystic ovary.

The disorders of endometrial receptivity and ovulatory dysfunction are both significant causes of infertility in patients with polycystic ovary syndrome (PCOS). In this study, we investigated the expression profile and functional implications of circular RNAs (circRNAs) in the endometrial receptivity of PCOS-affected mice. Twenty-four female C57BL/6 mice were divided into PCOS and normal control groups. The PCOS group received subcutaneous DHEA treatment, while the control group remained untreated. Gene chip technology was utilized to analyze circRNA expression in endometrial tissues on the fourth day of gestation with subsequent bioinformatics analyses into circRNA functions. Furthermore, endometrial epithelial cells were used to determine represented circRNA functions. Results showed that the PCOS group exhibited 205 differentially expressed circRNAs, with 147 upregulated and 58 downregulated ones. qRT-PCR confirmed differential expression of circRNAs, including circRNA_38548, circRNA_001686, circRNA_38550, and circRNA_27938. Predicted target genes and a circRNA-miRNA-mRNA regulatory network were constructed. Additionally, four circRNAs (circRNA_38548, circRNA_38550, and circRNA_001686) were identified to contribute to abnormal endometrial receptivity by regulating genes such as Lifr, FOXK1, FOXO1, HOXA10, through interactions with miRNAs. Further research is warranted to elucidate the underlying mechanisms involving these circRNAs.

Conversion of glucose to methyl glycolate in subcritical methanol.

Methyl glycolate (MG) is an important biodegradable PGA plastic monomer. Herein, a green approach to synthesize MG by methanolysis of glucose is proposed, in which the subcritical methanol and phenol/quinone redox system were combined to promote the reversible C-C cleavage and oxidation during the cascade reaction of glucose to MG.

Delayed tracheal rupture following transoral endoscopic thyroidectomy vestibular approach: Case report and review of the literature.

BACKGROUND: Although the transoral endoscopic thyroidectomy vestibular approach (TOETVA) has been proven to be a safe procedure for select patients, as it is a novel approach, all associated complications require adequate attention. METHODS: We presented a 49-year old woman who underwent TOETVA developed delayed tracheal rupture 1 week after surgery. An extensive search of literature was carried out using PubMed, Embase, and Web of Science for studies reporting tracheal injury following endoscopic thyroidectomy. RESULTS: Thirteen cases of endoscopic thyroidectomy were analyzed, including eight cases of TOETVA. Tracheal injury occurred during various procedures, including accidental dissection, surgical needle puncture, Hegar dilation and trocar placement, and thermal injury by the energy device. CONCLUSIONS: Tracheal injury following TOETVA is an underreported complication that can be induced by various factors. Thermal injury to the trachea is more likely to cause a delayed rupture. Careful blunt dissection and standardized use of energy devices are suggested.

Intraoperative near-infrared autofluorescence imaging for hypocalcemia risk reduction after total thyroidectomy: Evidence from a meta-analysis.

This meta-analysis evaluates whether near-infrared autofluorescence (NIRAF) imaging reduces the risk of hypocalcemia after total thyroidectomy. A systematic literature search in PubMed, EMBASE, Web of Science, and Cochrane Library for studies from June 2011 to January 2021 comparing total thyroidectomy with NIRAF and conventional surgery (naked eye). Six eligible studies involving 2180 patients were included. The prevalence of transient hypocalcemia was 8.11% (40/493) and 25.19% (425/1687) in the NIRAF and naked eye groups (p < 0.0001), respectively. The prevalence of permanent hypocalcemia was 0% (0/493) and 2.19% (37/1687) in the NIRAF and naked eye groups (p = 0.05), respectively. NIRAF reduces the risk of transient hypocalcemia and may possibly lower the rate of permanent hypocalcemia. Nonetheless, further studies are needed to verify our results and evaluate the cost-effectiveness of NIRAF in real-world clinical practice.

Mendelian Randomization Analysis Reveals Causal Effects of the Human Gut Microbiota on Abdominal Obesity.

BACKGROUND: Although recent studies have revealed an association between the composition of the gut microbiota and obesity, whether specific gut microbiota cause obesity has not been determined. OBJECTIVES: The aim of this study is to determine the causal relationship between specific gut microbiota and abdominal obesity. Based on genome-wide association study (GWAS) summary statistics, we performed a 2-sample Mendelian randomization (MR) analysis to evaluate whether the gut microbiota affects abdominal obesity. METHODS: Gut microbiota GWAS in 1126 twin pairs (age range, 18-89 years; 89% were females) from the TwinsUK study were used as exposure data. The primary outcome tested was trunk fat mass (TFM) GWAS in 492,805 participants (age range, 40-69 years; 54% were females) from the UK Biobank. The gut microbiota were classified at family, genus, and species levels. A feature was defined as a distinct family, genus, or species. MR analysis was mainly performed by an inverse variance-weighted test or Wald ratio test, depending on the number of instrumental variables (IVs) involved. A sensitivity analysis was performed on significant results by a weighted median test and a weighted genetic risk score (GRS) analysis. RESULTS: Results of MR analyses provided evidence of a causal association between 3 microbiota features and TFM, including 1 family [Lachnosiraceae; P = 0.02; ß = 0.001 (SEE, 4.28 × 10-4)], 1 genus [Bifidobacterium; P = 5.0 × 10-9; ß = -0.08 (SEE, 0.14)], and 1 species [Prausnitzii; P = 0.03; ß = -0.007 (SEE, 0.003)]. Both the weighted median test and GRS analysis successfully validated the association of the genetically predicted family, Lachnosiraceae (Pweighted median = 0.03; PGRS = 0.004). CONCLUSIONS: Our findings provided evidence of a causal association between gut microbiota and TFM in UK adults and identified specific bacteria taxa that may regulate the fat metabolism, thus offering new direction for the treatment of obesity.

Research progress of catalysts for synthesis of low-carbon alcohols from synthesis gas.

In recent years, the application value of low-carbon alcohols (C1-C6 alcohols) in the fuel, chemical, environmental protection and other fields has become increasingly prominent. Catalytic conversion of synthesis gas to low-carbon alcohol is one of the important ways to realize the industrial production of low-carbon alcohol. Lack of high-performance catalysts is the main reason that restricts the industrial development of producing low-carbon alcohols from synthesis gas. The construction of a dual active-center catalyst with high activity and stability, and the study of its function and catalytic mechanism have become significantly important. In this paper, the characteristics of the reaction process of syngas to low-carbon alcohols, and the catalytic mechanism and preparation methods of different catalyst systems were reviewed, which provide the basis for further research on high performance catalysts.

Effect of Cu-based metal organic framework (Cu-MOF) loaded with TiO2 on the photocatalytic degradation of rhodamine B dye.

Using copper nitrate trihydrate as the copper source, TiO2@Cu-MOF nanocomposites were prepared by a one-step crystallization method, and the effect of the amount of TiO2 loaded on the adsorption of rhodamine B was studied. X-ray diffraction (XRD), scanning electron microscope (SEM), energy spectrometer (EDS), N2 adsorption-desorption (BET), and infrared spectroscopy (FTIR) were used to characterize the microstructure and surface properties of composite materials. The results show that the composite material not only has a good degradability for rhodamine B, the decolorization rate reaches 98.03% after 120 min, but it also maintains a good cycle performance. Fitting the first-order kinetic equation to the reaction process, under the optimal conditions, R2 = 0.98, indicating that the reaction process conforms to the first-order kinetic equation. Therefore, the catalyst has good catalytic degradation and cycle performance.

Renewable Cyclopentanol From Catalytic Hydrogenation-Rearrangement of Biomass Furfural Over Ruthenium-Molybdenum Bimetallic Catalysts.

Biomass furfural-like compounds are chemicals that cannot be extracted from fossil materials, through which a large number of fine chemicals and fuel additives can be opened up, but one big efficiency problem during the transformation is the accumulation of oligomers. Here, we propose a novel and efficient Ru-Mo bimetallic catalyst for selective hydrogenation-rearrangement of furfural-like compounds. The result showed that an unprecedented rearrangement product selectivity of 89.1% to cyclopentanol was achieved under an optimized reaction condition over a 1%Ru-2.5%Mo/CNT catalyst reduced at 600°C. Subsequent characterization suggested that the catalyst presented with weak acidity and strong hydrogenation activity for the reaction, which not only ensures the smooth hydrogenation-rearrangement reaction but also inhibits the accumulation of furan polymers. These findings provide a convenient strategy to tune the catalytic performance of Mo-based catalysts by controlling the reduction and carburization conditions, which appear to be versatile for the rearrangement of furans and similar compounds.

Feasibility and safety of needle-assisted endoscopic thyroidectomy with lateral neck dissection for papillary thyroid carcinoma: a preliminary experience.

BACKGROUND: Endoscopic thyroidectomy is popular among patients with cosmetic requirements. However, when lateral neck dissection (LND) is required, endoscopic surgery may be challenging. Therefore, we introduced needle-assisted endoscopic technique to achieve endoscopic LND procedure and evaluated its safety and feasibility in the present study. METHODS: Medical records of 37 patients who underwent needle-assisted endoscopic thyroidectomy with LND were retrospectively reviewed. RESULTS: All of 37 patients had excellent cosmetic outcomes. The mean operative time was 338.2 ± 58.74 minutes. Mean number of lymph nodes retrieved in the lateral was 33.5 ± 11.69 and 15.9 ± 7.51 in the central neck. The rates of transient and permanent hypocalcemia were 32.4% and 2.7% and the rates of transient and permanent recurrent laryngeal nerve palsy were 8.1% and 0%, respectively. CONCLUSIONS: Needle-assisted endoscopic thyroidectomy with lateral neck dissection shows potential feasibility but further study is needed to better characterize its safety and applicability.

Effects of the 532-nm and 1,064-nm Q-switched Nd:YAG lasers on collagen turnover of cultured human skin fibroblasts: a comparative study.

Cultured human skin fibroblasts were irradiated twice successively with the 1.5 J/cm(2) of 532-nm and 1,064-nm lasers, respectively. The mRNA of procollagen, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), heat-shock protein 70 (Hsp70), interleukin-6 (IL-6) and transforming growth factor beta (TGF-beta) were analyzed at 24 and 48 h post-irradiation by using RT-PCR. Both lasers significantly increased the expression of type I and III procollagen, TIMP1, and TIMP2, but decreased MMP1 and MMP2 expression. The 1,064-nm laser initiated TGF-beta expression while the 532-nm laser elicited the increase of Hsp70 and IL-6. The increase/decrease rates of procollagen, TIMPs and MMPs for the 1,064-nm laser were higher than that of the 532-nm laser. Thus, both lasers effectively accelerated collagen synthesis and inhibited collagen degradation. Collagen synthesis induced by the 1,064-nm laser might be partly due to the upregulation of TGF-beta expression, while the increase of Hsp70 and IL-6 might be partly responsible for collagen synthesis stimulated by the 532-nm laser. With the parameters used in this study, the 1,064-nm infrared laser is more effective in promoting the beneficial molecular activities than the 532-nm visible laser.

[Effects of glucose concentration fluctuation on function of cultured bovine arterial endothelial cells].

OBJECTIVE: To explore the effects of glucose concentration fluctuation on function of cultured bovine arterial endothelial cells and underlying mechanism. METHODS: The thoracic aorta of newborn calf was used for primary endothelial cells culture. Cells were divided into 3 groups and cultured for 48 h: control group (C, 5.5 mmol/L), constant high glucose group (HG, 30 mmol/L) and glucose fluctuation (GF, three circles of 2 h 30 mmol/L followed by 3 h 5.5 mmol/L, 30 mmol/L overnight, repeat the whole procedure on the following day) groups. The membranes fluidity of endothelial cells was detected by fluorescence polarization method. The contents of sorbierite, aldose reductase (AR), sorbitol dehydrogenase (SDH) and advanced glycation end products (AGEs) were measured. RAGE, eNOS and ET-1 mRNA expressions were detected by semi-quantitative RT-PCR. RESULTS: The membranes fluidity of endothelial cells in HG or GF group were significantly decreased compared with the control group (all P < 0.01) and significantly lower in GF group than those in HG group (all P < 0.01). Sorbierite, AR and AGEs concentrations were significantly higher in HG and GF groups than those in control group (all P < 0.01) and AR and AGEs concentrations were significantly higher in GF group than that in HG group (all P < 0.01). SDH of endothelial cells in HG or GF group were decreased compared with the control group and lower in GF group than in HG group (all P < 0.05). In addition, the mRNA levels of RAGE, eNOS and ET-1 were significantly upregulated compared with the control group (all P < 0.01). CONCLUSIONS: Glucose concentration fluctuation can result in more severe bovine arterial endothelial cells dysfunction than high glucose via activating polyols metabolic pathways, upregulating the expression of AGEs, eNOS and ET-1. Therefore, glucose concentration fluctuation might play a crucial role on macrovascular complications of diabetes.