Photosynthesis and Carbon Metabolism

Photosynthesis takes place in chloroplasts of green plants and algae and results in the conversion of radiant energy into chemical energy. Water and carbon dioxide are the raw materials; plants can produce sugars by using chlorophyll and light energy. During the first reaction of photosynthesis, ATP and NADPH are produced from light energy. Oxygen and hydrogen are released from water broken during the light reaction. In the dark reaction, CO2 is converted into glucose by consuming energy that comes from first step of photosynthesis

PETA: Evaluating the Impact of Protein Transfer Learning with Sub-word Tokenization on Downstream Applications

Large protein language models are adept at capturing the underlying evolutionary information in primary structures, offering significant practical value for protein engineering. Compared to natural language models, protein amino acid sequences have a smaller data volume and a limited combinatorial space. Choosing an appropriate vocabulary size to optimize the pre-trained model is a pivotal issue. Moreover, despite the wealth of benchmarks and studies in the natural language community, there remains a lack of a comprehensive benchmark for systematically evaluating protein language model quality. Given these challenges, PETA trained language models with 14 different vocabulary sizes under three tokenization methods. It conducted thousands of tests on 33 diverse downstream datasets to assess the models' transfer learning capabilities, incorporating two classification heads and three random seeds to mitigate potential biases. Extensive experiments indicate that vocabulary sizes between 50 and 200 optimize the model, whereas sizes exceeding 800 detrimentally affect the model's representational performance. Our code, model weights and datasets are available at https://github.com/ginnm/ProteinPretraining.Comment: 46 pages, 4figures, 9 table

Prophylactic abdominal drainage following appendectomy for complicated appendicitis: A meta-analysis

BackgroundTo date, the value of prophylactic abdominal drainage (AD) following appendectomy in patients with complicated appendicitis (CA), including adults and children, has yet to be determined. This paper presents a meta-analysis of the effects of prophylactic AD on postoperative complications in patients with CA, with the goal of exploring the safety and effectiveness of prophylactic AD.MethodsPubMed, Science Direct, Web of Science, Cochrane Library, and Embase databases were searched for relevant articles published before August 1, 2022. The primary outcomes were the complication rates [overall incidence of postoperative complications, incidence of intra-abdominal abscess (IAA), wound infection (WI), and postoperative ileus (PI), and the secondary outcome was the perioperative outcome]. The meta-analysis was performed with STATA V. 16.0A.ResultsA total of 2,627 articles were retrieved and 15 high-quality articles were eventually included after screening, resulting in a total of 5,123 patients, of whom 1,796 received AD and 3,327 did not. The results of this meta-analysis showed that compared with patients in the non-drainage group, patients in the drainage group had longer postoperative length of hospitalization (LOH) (SMD = 0.68, 95% CI: 0.01–1.35, P = 0.046), higher overall incidence of postoperative complications (OR = 0.50, 95% CI: 0.19–0.81, P = 0.01), higher incidence of WI (OR = 0.30, 95% CI: 0.08–0.51, P = 0.01) and PI (OR = 1.05, 95% CI: 0.57–1.54, P = 0.01), the differences were statistically significant. However, there was no significant difference in the incidence of IAA (OR = 0.10, 95% CI: −0.10 to 0.31, P = 0.31) between the two groups. The results of subgroup meta-analysis showed that in the adult subgroup, the overall incidence of postoperative complications in the drainage group was higher than that in the non-drainage group (OR = 0.67, 95% CI: 0.37–0.96, P = 0.01). However, there were no significant differences in IAA (OR = 0.18, 95% CI: −0.28 to 0.64, P = 0.45) and WI (OR = 0.13, 95% CI: (−0.40 to 0.66, P = 0.63) and PI (OR = 2.71, 95% CI: −0.29 to 5.71, P = 0.08). In the children subgroup, there were no significant differences in the incidence of IAA (OR = 0.51, 95% CI: −0.06 to 1.09, P = 0.08) between the two groups. The overall incidence of postoperative complications (OR = 0.46, 95% CI: 0.02–0.90, P = 0.04), incidences of WI (OR = 0.43, 95% CI: 0.14–0.71, P = 0.01) and PI (OR = 0.75, 95% CI: 0.10–1.39, P = 0.02) were significantly higher than those in the non-drainage group.ConclusionThis meta-analysis concluded that prophylactic AD did not benefit from appendectomy, but increased the incidence of related complications, especially in children with CA. Thus, there is insufficient evidence to support the routine use of prophylactic AD following appendectomy

Improvement of Bondability by Depressing the Inhomogeneous Distribution of Nanoparticles in a Sintering Bonding Process with Silver Nanoparticles

Low-temperature bonding by sintering of Ag nanoparticles (NPs) is a promising lead-free bonding technique used in the electronic packaging industry. In this work, we prepare Ag nanoparticle (NP) paste using both an aqueous method and a polyol method. Sintering bonding trials were then conducted using different forms of Ag NPs. The results showed that use of the aqueous-based Ag NP paste led to inhomogeneous distribution of NPs, known as the ''coffee-ring effect.'' This led to low strength of fabricated joints. We investigated the influence of the coffeering effect and ways to depress it by changing the bonding material composition. Our results show that, when using polyol-based Ag NP paste as the bonding material, the coffee-ring effect was successfully depressed due to increased Marangoni flow. The corresponding shear strength of joints was increased significantly to 50 MPa at bonding temperature of 250°C

The mechanism of pore segregation in the sintered nano Ag for high temperature power electronics applications

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.matlet.2018.06.007 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/It is widely accepted that nano pores of sintered nanoparticles can coalesce into micro pores during high temperature service. When applying sintered nanoparticles in power electronics, the pore segregation and delamination seriously degrade the bond strength and thermal conductivity, but the reason is still not well understood. In this paper, both finite element analysis and experimental results confirmed that thermal stress is the main driving force for this phenomenon, which was not considered in the previous study. The effect of pore segregation on performance and reliability of power devices is also discussed.National Natural Science Foundation of China (51520105007, 51775299) National Key Research and Development Program of China (2017YFB1104900

Down-regulation of pancreatic and duodenal homeobox-1 by somatostatin receptor subtype 5: a novel mechanism for inhibition of cellular proliferation and insulin secretion by somatostatin

Somatostatin (SST) is a regulatory peptide and acts as an endogenous inhibitory regulator of the secretory and proliferative responses of target cells. SST's actions are mediated by a family of seven transmembrane domain G protein-coupled receptors that comprise five distinct subtypes (SSTR1-5). SSTR5 is one of the major SSTRs in the islets of Langerhans. Homeodomain-containing transcription factor pancreatic and duodenal homeobox-1 (PDX-1) is essential for pancreatic development, β cell differentiation, maintenance of normal β cell functions in adults and tumorigenesis. Recent studies show that SSTR5 acts as a negative regulator for PDX-1 expression and that SSTR5 mediates somatostatin's inhibitory effect on cell proliferation and insulin expression/excretion through down-regulating PDX-1 expression. SSTR5 exerts its inhibitory effect on PDX-1 expression at both the transcriptional level by down-regulating PDX-1 mRNA and the post-translational level by enhancing PDX-1 ubiquitination. Identification of PDX-1 as a transcriptional target for SSTR5 may help in guiding the choice of therapeutic cancer treatments