Defect-Free Alternating Conjugated Polymers Enabled by Room- Temperature Stille Polymerization

The Stille cross-coupling polymerization is one of the most efficient synthetic methods for donor-acceptor (D-A) type π-conjugated polymers (CPs). Nevertheless, thermal-activation Stille polymerization readily produced homocoupling defects, resulting in batch-to-batch variations in copolymers quality and deteriorating the device performance of electronics and optoelectronics. Here, a room-temperature Stille-type polymerization was developed, the utility and generality of which were demonstrated by synthesis of twelve D-A CPs with high molecular weights. Importantly, the resultant copolymers possessed no homocoupling (hc) structural defects, while hc reactions were observed in the thermal-activation Stille reactions. Thus, the organic field-effect transistors (OFETs) based on the former exhibited twofold higher charge transport mobility (2.10 cm²  V^-1  s^-1 ), since it possessed stronger crystallinity and lower trap density of states (tDOS).

A phase 2 study of sorafenib combined with conventional therapies in refractory central nervous system leukemia

BACKGROUND

Patients with refractory central nervous system leukemia (CNSL) have a dismal prognosis and lack effective therapy. Case reports have shown that sorafenib is effective against brain metastases, including leukemia.

METHODS

To explore the efficacy of sorafenib combined with conventional therapies for refractory CNSL, a phase 2 study was conducted. The primary end point was the complete remission rate (CRR) within 8 weeks of treatment. Secondary end points included the overall response rate (ORR), event-free survival (EFS), overall survival (OS), and adverse events (AEs).

RESULTS

Twenty-six patients with refractory CNSL were enrolled; they included 17 with isolated CNSL, 7 with hematological relapse, and 2 with another extramedullary relapse. After 8 weeks of treatment, 21 patients achieved complete remission, 2 achieved partial remission, and 3 achieved no remission for a CRR of 80.8% (95% CI, 62.1%-91.5%) and an ORR of 88.5% (95% CI, 71.0%-96.0%). Twenty patients survived, and 6 died. The 2-year EFS and OS rates were 75.0% (95% CI, 54.5%-88.3%) and 76.9% (95% CI, 54.2%-90.4%), respectively. Six patients experienced grade 3 or 4 treatment-related AEs, including moderate chronic graft-vs-host disease (n = 3), grade 3 or 4 acute graft-vs-host disease (n = 2), and grade 3 skin rash (n = 1). No treatment-related deaths occurred during the therapy of refractory CNSL.

CONCLUSIONS

Sorafenib combined with conventional therapies is effective and safe for refractory CNSL.

LAY SUMMARY

Sorafenib combined with conventional therapies is effective and safe for refractory central nervous system leukemia.

A clean process for phosphorus recovery and gallium enrichment from phosphorus flue dust by sodium carbonate roasting

Phosphorus flue dust (PFD) is a solid waste product from phosphorus (P) production that contains P and is enriched with gallium (Ga). The recovery of these valuable components not only protects the environment, but also reduces resource waste. This study aimed to develop a green and efficient method to recover P and enriched Ga from PFD. The effects of different parameters on the P leaching rate and Ga loss rate during Na₂CO₃ roasting and water leaching were investigated and optimized. The reaction mechanisms during the experiment were characterized, revealing that the P-containing compounds in PFD mainly transformed into water-soluble Na₃PO₄. Furthermore, the leaching rate of P reached 85.38%, while Ga was mainly concentrated in the residue and its loss rate was only about 1%. Ga content in the residue reached about 0.1%. An attempt was made to recover Na⁺ and PO₄^3- from the aqueous solution by evaporative crystallization and XRD analysis showed that the main phase of the crystallization product was Na₂HPO₄. The proposed process is technically simple, only Na₂CO₃ is added and no hazardous substances are generated, and represents a new method for recovering P and enriching Ga from PFD.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

The Relationship Between Obesity and Depression Is Partly Dependent on Metabolic Health Status: A Nationwide Inpatient Sample Database Study

OBJECTIVE

Some studies have demonstrated a bidirectional association between obesity and depression, whereas others have not. This discordance might be due to the metabolic health status. We aimed to determine whether the relationship between obesity and depression is dependent on metabolic health status.

METHODS

In total, 9,022,089 participants were enrolled and classified as one of four obesity phenotypes: metabolically healthy nonobesity (MHNO), metabolically unhealthy nonobesity (MUNO), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUO). We then divided the population into eight phenotypes based on obesity and the number of metabolic risk factors. Furthermore, the associations of eight phenotypes, based on obesity and specific metabolic risk factors, with depression were assessed.

RESULT

Among all participants, a higher risk of depression was observed for MUNO, MHO and MUO than for MHNO. The risk was highest for MUO (OR = 1.442; 95% CI = 1.432, 1.451). However, the association between MHO and depression was different for men and women (OR = 0.941, men; OR = 1.132, women). The risk of depression increased as the number of metabolic risk factors increased. Dyslipidemia was the strongest metabolic risk factor. These relationships were consistent among patients ≥ 45 years of age.

CONCLUSIONS

The increased risk of obesity-related depression appears to partly depend on metabolic health status. The results highlight the importance of a favorable metabolic status, and even nonobese populations should be screened for metabolic disorders.

Synchronization of Cultured Cells to G1, S, G2, and M Phases by Double Thymidine Block

The typical cell cycle in eukaryotes is composed of four phases including the G1, S, G2, and M phases. G1, S, and G2 together are called interphase. Cell synchronization is a process that brings cultured cells at different stages of the cell cycle to the same phase. For many experiments, it is desirable to have a population of cells that are traversing the cell cycle synchronously, as it allows population-wide data to be collected rather than relying solely on single-cell experiments. While there are various drugs that can be used to arrest the cell at each specific phase of the cell cycle, they may cause undesired side effects. Here, we describe a protocol to synchronize cells to each cell cycle phase by using only one chemical: thymidine. Non-synchronized cells are synchronized to early S phase by a double thymidine block. The release of the double thymidine block allows the cells to progress through the cell cycle in a synchronized pace. By collecting the cells at various time intervals following the release of double thymidine block, we are able to harvest cells synchronized to the G2, M, and G1 phases. This synchronization can be assessed by various methods, including flow cytometry to examine the DNA content, Western blotting to examine the expression of various cell phase-specific markers, and microscopy to examine the morphology of the chromosome.

Effects of novel cellulase (Cel 906) and probiotic yeast fermentation on antioxidant and anti-inflammatory activities of vine tea (Ampelopsis grossedentata)

Vine tea (Ampelopsis grossedentata) is a plant resource with good nutritional and medicinal, and is widely consumed in China. This study aimed to develop a functional vine tea fermentation broth using microbial fermentation and cellulase degradation. First, the most suitable probiotics for vine tea fermentation were screened, and the fermentation conditions were optimized. Then, a new cellulase (Cel 906, MW076177) was added to evaluate the changes in the contents of effective substances and to study its efficacy. The results show that saccharomyces cerevisiae Y-401 was identified as the best strain, the optimal fermentation conditions were a time of 94.60 h, feeding concentration of 115.21 g/L, and temperature of about 34.97°C. The vine tea fermentation broth has a strong inhibitory ability on 2,2'-azinobis3-ethylbenzothiazoline-6-sulfonic acid (ABTS) (99.73%), peroxyl (53.15%), superoxide anion radicals (84.13%), and 1,1-Diphenyl-2-trinitrophenylhydrazine (DPPH) (92.48%). It has a decent inhibitory impact on the cell viability, tyrosinase activity (32.25%), and melanin synthesis (63.52%) of B16-F10 melanoma cells induced by α-MSH. Inflammatory cell recruitment was reduced in a zebrafish inflammation model. Therefore, this vine tea fermented broth has strong antioxidant, anti-melanoma, and anti-inflammatory effects, and has healthcare potential as a probiotic tea.

Synchronization of HeLa Cells to Various Interphases Including G1, S, and G2 Phases

The typical cell cycle in eukaryotes is composed of four phases including the G1, S, G2, and M phases. G1, S, and G2 together are called interphase. Cell synchronization is a process that brings cultured cells at different stages of the cell cycle to the same phase, which allows the study of phase-specific cellular events. While interphase cells can be easily distinguished from mitotic cells by examining their chromosome morphology, it is much more difficult to separate and distinguish the interphases from each other. Here, we describe drug-derived protocols for synchronizing HeLa cells to various interphases of the cell cycle: G1 phase, S phase, and G2 phase. G1 phase synchronization is achieved through serum starvation, S phase synchronization is achieved through a double thymidine block, and G2 phase synchronization is achieved through the release of the double thymidine block followed by roscovitine treatment. Successful synchronization can be assessed using flow cytometry to examine the DNA content and Western blot to examine the expression of various cyclins.

Synchronization of HeLa Cells to Mitotic Subphases

The cell cycle is a series of events leading to cell replication. When plated at low cell densities in serum-containing medium, cultured cells start to proliferate, moving through the four phases of the cell cycle: G1, S, G2, and M. Mitosis is the most dynamic period of the cell cycle, involving a major reorganization of virtually all cell components. Mitosis is further divided into prophase, prometaphase, metaphase, anaphase, and telophase, which can be easily distinguished from one another by protein markers and/or comparing their chromosome morphology under fluorescence microscope. The progression of the cell cycle through these mitotic subphases is tightly regulated by complicated molecular mechanisms. Synchronization of cells to the mitotic subphases is important for understanding these molecular mechanisms. Here, we describe a protocol to synchronize Hela cells to prometaphase, metaphase, and anaphase/telophase. In this protocol, Hela cells are first synchronized to the early S phase by a double thymidine block. Following the release of the block, the cells are treated with nocodazole, MG132, and blebbistatin to arrest them at prometaphase, metaphase, and anaphase/telophase, respectively. Successful synchronization is assessed using Western blot and fluorescence microscopy.

BrdU Incorporation Assay to Analyze the Entry into S Phase

5-Bromo-2'-deoxyuridine (bromodeoxyuridine (BrdU)), a modified nucleotide and analog of thymidine, is commonly used for detecting proliferating cells. For detection, an anti-BrdU antibody (probe) with a fluorescent dye is applied to bind the BrdU label after DNA denaturation. In this protocol, we provide the BrdU labeling method for both in vitro and in vivo studies, along with immunocytochemistry (ICC)/immunofluorescence (IF) and immunohistochemistry (IHC) staining procedures, respectively. Multicolor staining is also presented as an option to detect the co-distribution of two or multiple antigens in the same sample, making it possible to visualize the location of different molecules at the same time.

Analysis of Cell Cycle by Flow Cytometry

The cell cycle of a cell is tightly controlled by several regulators. Dysregulation of cell cycle can lead to uncontrolled cell division which is one of the main characteristics of cancer cells. DNA content of a cell is changed during the cell cycle progression and can be measured by flow cytometry. In this chapter, we aim to provide a detailed protocol on how to analyze the cell cycle using flow cytometry.

Cell Cycle Progression and Synchronization: An Overview

The cell cycle is the series of events that take place in a cell that drives it to divide and produce two new daughter cells. Through more than 100 years of efforts by scientists, we now have a much clearer picture of cell cycle progression and its regulation. The typical cell cycle in eukaryotes is composed of the G1, S, G2, and M phases. The M phase is further divided into prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that controls the activity of various Cdk-cyclin complexes. Most cellular events, including DNA duplication, gene transcription, protein translation, and post-translational modification of proteins, occur in a cell-cycle-dependent manner. To understand these cellular events and their underlying molecular mechanisms, it is desirable to have a population of cells that are traversing the cell cycle synchronously. This can be achieved through a process called cell synchronization. Many methods have been developed to synchronize cells to the various phases of the cell cycle. These methods could be classified into two groups: synchronization methods using chemical inhibitors and synchronization methods without using chemical inhibitors. All these methods have their own merits and shortcomings.

A radiomics nomogram for the ultrasound-based evaluation of central cervical lymph node metastasis in papillary thyroid carcinoma

PURPOSE

To develop and validate a radiomics nomogram based on ultrasound (US) to predict central cervical lymph node (LN) metastasis in patients with papillary thyroid carcinoma (PTC).

METHODS

PTC patients with pathologically confirmed presence or absence of central cervical LN metastasis in our hospital between March 2021 and November 2021 were enrolled as the training cohort. Radiomics features were extracted from the preoperative US images, and a radiomics signature was constructed. Univariate and multivariate logistic regression analyses were used to screen out the independent risk factors, and a radiomics nomogram was established. The performance of the model was verified in the independent test cohort of PTC patients who underwent thyroidectomy and cervical LN dissection in our hospital from December 2021 to March 2022.

RESULTS

In the independent test cohort, the radiomics model based on long-axis cross-section and short-axis cross-section images outperformed the radiomics models based on either one of these sections (the area under the curve (AUC), 0.69 vs. 0.62 and 0.66). The radiomics signature consisted of 4 selected features. The US radiomics nomogram included the radiomics signature, age, gender, BRAF V600E mutation status, and extrathyroidal extension (ETE) status. In the independent test cohort, the AUC of the receiver operating curve(ROC) of this nomogram was 0.76, outperformingthe clinical model and the radiomics model (0.63 and 0.69, respectively), and also much better than preoperative US examination (AUC, 0.60). Decision curve analysis indicated that the radiomics nomogram was clinically useful.

CONCLUSIONS

This study presents an efficient and useful US radiomics nomogram that can provide comprehensive information to assist clinicians in the individualized preoperative prediction of central cervical LN metastasis in PTC patients.

Cidofovir, a choice for salvage treatment of CMV infection in patients with haploidentical hematopoietic stem cell transplantation

BACKGROUND

Cidofovir (CDV) is a nucleotide analogue with broad antiviral activities. It remains unclear about the CDV administration for anti-cytomegalovirus (CMV) treatment in patients with haploidentical hematopoietic stem cell transplantation (haplo-HSCT).

PATIENTS AND METHODS

In this study, 31 out of 101 haplo-HSCT recipients suffered CMV infection in the CT group (conventional treatment) were enrolled into the CDV-ST group (CDV-second-line treatment). These patients were treated with CDV as they failed conventional treatment or they were unavailable to the preemptive antiviral therapy. Nine patients with CMV infection were enrolled into the CDV-FT group (CDV-frontline treatment) and received CDV preemptive therapy.

RESULTS

In the CDV-ST group, 23/28(82.1%) patients were observed treatment response with a median time of 9 (2-23) days, and 20 (71.8%) among these patients obtained complete response (CR). In the CDV-FT group, 6/8 (75.0%) patients acquired CR with a median of 6 (4-25) days. The treatment response in CDV-treated groups was comparable with those in CT groups. Besides, there was no statistical difference in CMV-related mortality between the three groups (P>0.05). During the follow-up period (Median follow-up:10 (1-28) months), a total of 8/22 (36.4%) patients experienced CMV reactivation in the CDV-ST group, versus 23/62 (37.1%) in CT group (P>0.05). CDV-related toxicities occurred in 13/40 (32.5%) patients, including 6 (15%) reversible nephrotoxicity.

CONCLUSION

Our study suggests that CDV is potentially an option for the salvage treatment of CMV infection in the haplo-HSCT patients. This article is protected by copyright. All rights reserved.

[Analysis of influencing factors of work-related musculoskeletal disorders of workers in a cabinet factory]

Objective: To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in the cabinet factory workers, and explore the influencing factors of workers' WMSDs. Methods: A cross-sectional survey method was used to investigate the risk factors such as basic conditions, labox dnganiza, ergonomics load and occurrence of WMSDs of 821 workers in a cabinet factory of a furniture manufacturing company in Guangdong Province using the electronic version of the Musculoskeletal Injury Questionnaire from October to December 2019. χ(2) test and logistic regression were used to analyze the risk factors leading to WMSDs. Results: The incidence of WMSDs in cabinet production workers reached 51.5% (423/821) , and the top three incidences were shoulder (28.4%, 233/821) , neck (28.1%, 231/821) , and wrist (25.9%, 213/821) . The incidence of neck WMSDs was statistically significant among different types of work (P<0.05) . Multiple repetitive operations per minute (OR=1.70) , torso often maintaining the same posture (OR=1.61) , turning heads for a long time (OR=1.58) and frequent heavy lifting (OR=1.44) were risk factors for the occurrence of shoulder WMSDs (P<0.05) . Frequent maintenance of the same posture in the neck (OR=1.91) , repeated operations per minute (OR=1.87) , shortage of department staff (OR=1.65) and turning head for a long time (OR=1.48) were risk factors for the occurrence of neck WMSDs (P<0.05) . Long-term bending of the wrist (OR=2.25) , grasping objects tightly (OR=2.13) , working hard on the upper limbs or hands (OR=1.91) , shortage of department personnel (OR=1.84) , repeated operations per minute (OR=1.68) and the use of vibration tools (OR=1.51) were risk factors for the occurrence of WMSDs in the wrist (P<0.05) . Conclusion: The incidence of WMSDs in cabinet factory is relatively high, the occurrence of WMSDs in the shoulders, necks and wrists is more serious. Reasonable labor organization and reducing the load of poor ergonomics in the workplace, can reduce the occurrence of WMSDs in production workers.

[Clinical significance of the deep learning algorithm based on contrast-enhanced CT in the differential diagnosis of gastric gastrointestinal stromal tumors with a diameter ≤ 5 cm]

Objective: Contrast-enhanced CT is an important method of preoperative diagnosis and evaluation for the malignant potential of gastric submucosal tumor (SMT). It has a high diagnostic accuracy rate in differentiating gastric gastrointestinal stromal tumor (GIST) with a diameter greater than 5 cm from gastric benign SMT. This study aimed to use deep learning algorithms to establish a diagnosis model (GISTNet) based on contrast-enhanced CT and evaluate its diagnostic value in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before surgery. Methods: A diagnostic test study was carried out. Clinicopathological data of 181 patients undergoing resection with postoperative pathological diagnosis of gastric SMT with a diameter ≤ 5 cm at Department of Gastrointestinal Surgery of Renji Hospital from September 2016 to April 2021 were retrospectively collected. After excluding 13 patients without preoperative CT or with poor CT imaging quality, a total of 168 patients were enrolled in this study, of whom, 107 were GIST while 61 were benign SMT (non-GIST), including 27 leiomyomas, 24 schwannomas, 6 heterotopic pancreas and 4 lipomas. Inclusion criteria were as follows: (1) gastric SMT was diagnosed by contrast-enhanced CT before surgery; (2) preoperative gastroscopic examination and biopsy showed no abnormal cells; (3) complete clinical and pathological data. Exclusion criteria were as follows: (1) patients received anti-tumor therapy before surgery; (2) without preoperative CT or with poor CT imaging quality due to any reason; (3) except GIST, other gastric malignant tumors were pathologically diagnosed after surgery. Based on the hold-out method, 148 patients were randomly selected as the training set and 20 patients as the test set of the GISTNet diagnosis model. After the GISTNet model was established, 5 indicators were used for evaluation in the test set, including sensitivity, specificity, positive predictive value, negative predictive value and the area under the receiver operating curve (AUC). Then GISTNet diagnosis model was compared with the GIST-risk scoring model based on traditional CT features. Besides, in order to compare the accuracy of the GISTNet diagnosis model and the imaging doctors in the diagnosis of gastric SMT imaging, 3 radiologists with 3, 9 and 19 years of work experience, respectively, blinded to clinical and pathological information, tested and judged the samples. The accuracy rate between the three doctors and the GISTNet model was compared. Results: The GISTNet model yielded an AUC of 0.900 (95% CI: 0.827-0.973) in the test set. When the threshold value was 0.345, the sensitivity specificity, positive and negative predictive values of the GISTNet diagnosis model was 100%, 67%, 75% and 100%, respectively. The accuracy rate of the GISTNet diagnosis model was better than that of the GIST-risk model and the manual readings from two radiologists with 3 years and 9 years of work experience (83% vs. 75%, 60%, 65%), and was close to the manual reading of the radiologist with 19 years of work experience (83% vs. 80%). Conclusion: The deep learning algorithm based on contrast-enhanced CT has favorable and reliable diagnostic accuracy in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before operation.

Rosamultin from Potentilla anserine L. exhibits nephroprotection and antioxidant activity by regulating the reactive oxygen species/C/EBP homologous protein signaling pathway

Rosamultin, a major bioactive constituent from Potentilla anserine L., has antioxidative and hepatoprotective activities. However, its protective effects on cisplatin-induced acute renal injury and the underlying mechanisms remain elusive. In this work, rosamultin could enhance the viability of HEK293 cells treated by cisplatin. In vivo experiment showed that rosamultin effectively decreased kidney index, reduced blood urea nitrogen level, decreased urinary protein excretion, and ameliorated the histopathological damage and fibrosis of renal tissue induced by cisplatin. Besides, rosamultin showed no obvious toxicity in mice. SILAC-based quantitative proteomic analysis identified 4,461 proteins and eight proteins including C/EBP homologous protein (CHOP) were markedly decreased in cisplatin-treated HEK293 cells when exposed to rosamultin. Biochemical experiments further discovered that rosamultin could inhibit p38 and JNK activation, and downregulate the levels of CHOP and proteins in its upstream PERK-eIF2α-ATF4 signaling pathway stimulated by cisplatin or tunicamycin. At the same time, rosamultin reduced the generation of intracellular ROS induced by cisplatin and enhanced the activities of antioxidant enzymes such as SOD, GSH, and CAT. Moreover, rosamultin markedly suppressed the expression of CHOP, apoptosis-associated proteins, and activation of p38 and JNK in renal tissue. These findings suggest that rosamultin might be a potential protectant against cisplatin-induced nephrotoxicity.