Synthesis and properties of block copolymers composed of norbornene/higher α-olefin gradient segments using ansa-fluorenylamidodimethyltitanium-[Ph3C][B(C6F5)4] catalyst system

A series of di- and triblock copolymers composed of gradient norbornene (NB)/α-olefin segments were synthesized by a (t-BuNSiMe₂Flu)TiMe₂-based catalyst and their physical and mechanical properties were investigated.

Transcriptome analysis of sheep follicular development during prerecruitment, dominant, and mature stages after FSH superstimulation

Sheep is usually a monovular animal; superovulation technology is used to increase the number of offspring per individual and shorten generation intervals. To date, mature FSH superstimulatory treatments have been successfully used in sheep breeding, but much remains unknown about genes, pathways, and biological functions involved in follicular development. Therefore, in this study, we performed transcriptome profiling of small follicles (SFs; 2-2.5 mm), medium follicles (MFs; 3.5-4.5 mm), and large follicles (LFs; > 6 mm) in Mongolian ewes after FSH superstimulation. Furthermore, we identified differentially expressed genes and performed Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology enrichment analyses in 3 separate pairwise comparisons. We found that ovarian steroidogenesis was significantly enriched in the SFs versus MFs analysis; the associated genes, cytochrome P450 family 19 (CYP19) and Hydroxy-delta-5-steroid dehydrogenase 3 beta- and steroid delta-isomerase 1 (HSD3B1), were significantly upregulated. Moreover, proline metabolism, glutathione metabolism, and PPAR signaling pathways were significantly enriched in the LFs versus SFs analysis; the associated genes, glutamate-cysteine ligase modifier subunit (GCLM) and cystathionine gamma-lyase (CTH), were significantly upregulated, whereas peroxisome proliferator-activated receptor gamma (PPARγ) was significantly downregulated. In summary, our study provides basic data and possible biological direction to further explore the molecular mechanism of sheep follicular development after FSH superstimulation.

Genetic variants in long non-coding RNAs UCA1 and NEAT1 were associated with the prognosis of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is known for its high incidence, death rate, and relatively low 5-year survival. Long non-coding RNAs (lncRNAs) have been shown to play a significant role in cancerization and cancer progression. However, research on the association of polymorphisms in these lncRNAs with the prognosis of OSCC is lacking. Fifteen functional single-nucleotide polymorphisms (SNPs) in seven lncRNAs were selected to explore the relationship between these lncRNA SNPs and the prognosis among 209 OSCC patients. Kaplan-Meier analysis and Cox proportional hazards regression models were used to examine the associations. Further functional exploration of significant SNPs was done by eQTL analysis. Using multivariate Cox hazards regression analysis, a predictive role of NEAT1 rs3741384 GG and UCA1 rs7255437 TC+TT in a worse prognosis of OSCC was identified. In addition, a marked increased risk of death was observed with an increasing number of unfavourable genotypes (NUG). The NUG was then incorporated with clinical variables in the receiver operating characteristic curve, and the results indicated a potential role of the NUG in predicting OSCC patient risk of death (area under the curve increase from 0.616 to 0.703). In conclusion, the study findings indicate that genetic variants rs3741384 in NEAT and rs7255437 in UCA1 may influence the survival of OSCC patients.

Ultra-low-dose CT reconstructed with ASiR-V using SmartmA for pulmonary nodule detection and Lung-RADS classifications compared with low-dose CT

AIM

To evaluate the accuracy of ultra-low-dose computed tomography (ULDCT) with ASiR-V using a noise index (SmartmA) for pulmonary nodule detection and Lung CT Screening Reporting And Data System (Lung-RADS) classifications compared with low-dose CT (LDCT).

MATERIALS AND METHODS

Two-hundred and ten patients referred for lung cancer screening underwent conventional chest LDCT (0.80 ± 0.28 mSv) followed immediately by ULDCT (0.16 ± 0.03 mSv). ULDCT was scanned using 120 kV/SmartmA with a noise index of 28 HU and reconstructed with ASiR-V70%. The types and diameters of all nodules were recorded. The attenuation of pure ground-glass nodules (pGGNs) was measured on LDCT. All nodules were further classified using Lung-RADS. Sensitivities of nodule detection on ULDCT were analysed using LDCT as the reference standard. Logistic regression was used to establish a prediction model for the sensitivity of nodules.

RESULTS

LDCT revealed 362 nodules and the overall sensitivity on ULDCT was 90.1%. The sensitivity for solid nodules (SNs) of ≥1 mm diameter was 96.6% (228/236) and 100% (26/26) for SNs of ≥6 mm diameter. For pGGNs of ≥6 mm, the overall sensitivity was 93% (40/43) and 100% (29/29) for nodules with a attenuation value -700 HU or more. The agreement of Lung-RADS classification between two scans was good. On logistic regression, diameter was the only independent predictor for sensitivity of SNs (p<0.05). Diameter and attenuation value were predictors for pGGNs (p<0.05).

CONCLUSION

ULDCT with ASiR-V using SmartmA is suitable for lung-cancer screening in people with a BMI ≤35 kg/m² as it has a low radiation dose of 0.16 mSv, high sensitivity for nodule detection and good performance of Lung-RADS classifications.

Distributions of time, place, and population of novel coronavirus disease 2019 (COVID-19) from January 20 to February 10, 2020, in China

Background and objective

Since December 2019, increasing cases of novel coronavirus disease 2019 (COVID-19) are being detected worldwide. The purpose of this paper is to provide a scientific reference for the global prevention and control of COVID-19.

Methods

General demographic characteristics, epidemiological history, and clinical symptoms of COVID-19 were collected that had been reported on the websites of multiple Municipal Health Commissions in China. We herein describe distributions in time, place, and population of COVID-19.

Results

As of midnight on February 10, 2020, the number of confirmed cases of COVID-19 in China was 42,638, and the province with the largest number of confirmed cases was Hubei (31,728), followed by Guangdong (1177), Zhejiang (1117), and Henan (1105) province. The number of cases and the speed of confirmed cases in provinces other than Hubei were more moderate than those of the Hubei province. The median (interquartile range) age of 1740 patients with COVID-19 was 44 (33, 54) years, with a range of 10 months to 89 years.

Conclusions

The COVID-19 epidemic should be considered a global threat and the steps for control include early diagnosis and treatment, as well as isolation.

[Distributions of time, place, and population of novel coronavirus disease 2019 (COVID-19) from January 20 to February 10, 2020, in China]

Background and objective

Since December 2019, increasing cases of novel coronavirus disease 2019 (COVID-19) are being detected worldwide. The purpose of this paper is to provide a scientific reference for the global prevention and control of COVID-19.

Methods

General demographic characteristics, epidemiological history, and clinical symptoms of COVID-19 were collected that had been reported on the websites of multiple Municipal Health Commissions in China. We herein describe distributions in time, place, and population of COVID-19.

Results

As of midnight on February 10, 2020, the number of confirmed cases of COVID-19 in China was 42,638, and the province with the largest number of confirmed cases was Hubei (31728), followed by Guangdong (1177), Zhejiang (1117), and Henan (1105) province. The number of cases and the speed of confirmed cases in provinces other than Hubei were more moderate than those of the Hubei province. The median (interquartile range) age of patients with COVID-19 was 44 (33, 54) years, with a range of 10 months to 89 years.

Conclusions

The COVID-19 epidemic should be considered a global threat and the steps for control include early diagnosis and treatment, as well as isolation.

Skeletal, dental and facial aesthetic changes following anterior maxillary segmental distraction by tooth-borne device in patients with cleft lip and palate

Maxillary skeletal deficiency secondary to cleft lip and palate (CLP) remains a significant challenge. The aim of this study was to present the comprehensive skeletal, dental and facial aesthetic outcomes of anterior maxillary segmental distraction osteogenesis (AMSDO) for treatment of maxillary hypoplasia in patients with CLP. Twelve patients with maxillary hypoplasia treated with AMSDO by a customized tooth-borne distractor were included. Three-dimensional changes of anterior maxillary segment, upper incisor and pharyngeal space were measured by three-dimensional reconstruction derived from cone beam computed tomography (CBCT) data. Length and width of dental arch during distraction were determined in dental casts. Nasolabial angle, soft-tissue convexity and patient's subjective satisfaction were assessed to evaluate facial aesthetic improvements. Nasopharyngoscopic evaluation and speech assessment were also performed before and after distraction. All patients successfully received AMSDO without serious complications. Following AMSDO, the anterior maxillary segments moved forward 5.56±0.28mm and slightly upward 1.15±0.13mm. AMSDO significantly lengthened maxillary dental arch, generated new bone to relieve dental crowding and improved patients' facial aesthetic without worsening velopharyngeal closure and speech quality. AMSDO by tooth-borne distractor is an effective surgical alternative for the advancement in patients with cleft maxillary hypoplasia.

[Research progress in standardized dental treatments of patients receiving bisphosphonate]

Bisphosphonate (BP), a group of anti-resorptive drugs, has been widely used for the treatments of osteoporosis and metastatic bone diseases. Medication-related osteonecrosis of the jaw (MRONJ), a serious well-recognized complication of patients receiving BP, adversely affects patients' oral health and quality of life. Its clinical signs include pain, bone exposure and necrosis of the jaws. Invasive oral treatments, which may affect the repair of jaws in patients using BP, could cause the occurrence of MRONJ. Therefore, it is important to avoid the risk factors of MRONJ and to standardize the operations in order to reduce the occurrence of MRONJ in oral treatments for patients receiving BP. After reviewing the related literature, this article aims to conclude the research progress on the standardized oral treatments of patients receiving BP and to provide clinical instructions for clinicians to treat these patients.

[Effect of fragmented sleep on postoperative cognitive function and central neuroinflammation]

Objective: To investigate the effect of sleep fragmentation on perioperative neurocognitive disorders (PND) and central neuroinflammation by simulating sleep patterns of postoperative patients with sleep fragmentation in aged mice. Methods: Thirty-two elderly ICR mice were randomly divided into four groups (n=8): normal group (C), surgery group (S), fragmented sleep group (F), and surgery+fragmented sleep group (D). Fragmented sleep was conducted after internal fixation of tibia fractures, cognitive function was evaluated by novel object recognition (NOR) and fear conditioning (FC) test, and changes in expression of inflammatory cytokines in hippocampus were detected by ELISA. Results: NOR test: the recognition index (RI) of mice in group C, group S, group F and group D was 0.69±0.07, 0.48±0.07, 0.54±0.10 and 0.50±0.12, respectively. The RI of mice in group S, group F and group D was significantly lower than that in group C (t=4.885, 3.521 and 4.433, all P<0.01). There was no significant difference in RI between group S and group D (t=0.967 1, P>0.05). Contextual FC test: the freezing time of mice in group C, group S, group F and group D was(21.34±6.48), (13.83±4.26), (11.50±6.25) and (6.17±4.77) s, respectively. The freezing time of mice in group S, group F and group D was significantly lower than that in group C (t=2.722, 3.566, 5.496, P<0.05 or P<0.01). The freezing time of mice in group D was significantly lower than that in group S (t=2.774, P<0.05). Cue FC test: the freezing time of mice in group C, group S, group F and group D was (74.36±17.09), (43.91±9.71), (46.34±13.43) and (24.90±14.21) s, respectively. The freezing time of mice in group S, group F and group D was significantly lower than that in group C (t=4.393, 4.043 and 7.136, all P<0.01). The freezing time of mice in group D was significantly lower than that in group S (t=2.743, P<0.05). The levels of TNF-α, IL-6 and IL-1β in hippocampus of mice in group S, F and D were significantly higher than those in group C, while the levels of TNF-α and IL-6 in hippocampus of mice in group D were significantly higher than those in group S, with statistically significant differences (P<0.05 or P<0.01). Conclusion: Postoperative fragmented sleep aggravates postoperative cognitive impairment and increases the hippocampal neuroinflammation in aged mice.

A robust model for estimating thermal conductivity of liquid alkyl halides

Thermal conductivity is an essential thermodynamic property in chemical engineering application. As a result, estimating the thermal conductivity of organic compounds is of significance in industry production. Alkyl halides are important organic intermediates and raw materials, but little investigations have been performed to estimate their thermal conductivity. In this study, the structures of compounds were optimized in Gaussian 09W and molecular descriptors were extracted by Dragon software. Finally, we developed a 6-descriptor linear quantitative structure-property relationship (QSPR) model to estimate the thermal conductivity of alkyl halides using the genetic function approximation (GFA) method. Validation proved that the developed model had goodness-of-fit, robustness and predictive ability. The r²_pred and root-mean-square error (RMSE_P) of prediction set for the model were equal to 0.9745 and 0.0035, respectively. Meanwhile, the applicability domain was visualized by means of the Williams plot. This study provides a new model for estimating the thermal conductivity of this important class of chemicals.

Pb and Li co-doped NiOx for efficient inverted planar perovskite solar cells

Organic-inorganic halide perovskites solar cells have garnered increasing attention in recent years due to the dramatic rise in power conversion efficiencies (PCEs). In perovskite solar cells (PSCs), selecting appropriate hole transport materials to insert between perovskite layer and electrodes can improve Schottky contact, facilitate the hole transport, therefore reduce charge recombination, and therefore improve cell performance. Doping of metal cation is an effective means to regulate energy level structure and change its conductivity. In this study, we novelly introduce the Pb²⁺ doped NiOx as the hole transport materials to decrease the energy loss between NiOx and the perovskite layer, which improves open-circuit voltage (Voc) of the PSCs. In order to improve the conductivity of the NiOx film, the Li⁺ co-doping is introduced. We introduce Pb and Li co-doping strategy to match the work function of doped NiOx with perovskite valence band energy level, and increase the conductivity of NiOx for high-efficiency inverted planar PSCs. The Pb and Li co-doped NiOx devices exhibit efficient hole extraction and enhanced conductivity, which improve the performance of inverted planar PSCs to 17.02% compared with 15.40% of the undoped device.

[Spectrum analysis of pathological classification in 463 cases with nasal and paranasal sinuses malignant tumors]

Objective:The characteristics of pathological histological classification of nasal and paranasal sinuses malignant tumors in the past 10 years were analyzed, so as to provide possible basis, direction and ideas for the development of relevant effective treatment measures for nasal and paranasal sinuses malignant tumors in clinical practice. Method:The clinical data of patients with nasal and paranasal sinuses malignant tumors admitted to PLA general hospital from January 2009 to December 2018 were collected. Pathological types were retrospectively analyzed, and disease spectrum distribution, composition ratio and variation tendency of these patients were calculated. Result:Among the 463 patients, the overall pathological types in the top 5 were as follows: squamous cell carcinoma, adenoid cystadenocarcinoma, olfactory neuroblastoma, melanoma, adenocarcinoma. As for male patients, the pathological types in the top 5 were squamous cell carcinoma, adenoid cystic carcinoma, olfactory neuroblastoma, adenocarcinoma, neuroendocrine carcinoma and rhabdomyosarcoma were tied for fifth; the top 5 most common pathological types in female patients were squamous cell carcinoma, adenoid cystic carcinoma, melanoma, rhabdomyosarcoma, and adenocarcinoma. From 2009 to 2013, there were 183 patients with nasal and paranasal sinuses malignant tumors, the top 5 pathological types were squamous cell carcinoma, adenoid cystadenocarcinoma, olfactory neuroblastoma, melanoma, neuroendocrine carcinoma and rhabdomyosarcoma were tied for fifth; From 2014 to 2018, 280 patients with nasal and paranasal sinuses malignant tumors were diagnosed, the top 5 pathological types were squamous cell carcinoma, adenoid cystadenocarcinoma, melanoma, adenocarcinoma, and rhabdomyosarcoma. The ratio of the number of patients from 2009 to 2013 and 2014 to 2018 was about 0.65∶1. Malignant tumors of the nasal and paranasal sinuses tend to occur between the ages of 41 and 60, and the pathological types in the top 5 were squamous cell carcinoma,adenoid cystic carcinoma, adenocarcinoma, melanoma, neuroendocrine carcinoma. Conclusion:Malignant tumors of nasal cavity and sinus were more common in male, and the pathological types such as squamous cell carcinoma, adenoid cystic carcinoma, olfactory neuroblastoma were more common. All age groups have the disease, but the age group of 41-60 years old is the high-risk group of nasal and nasal sinus malignant tumors. However, the incidence rate of melanoma has gradually increased in the past five years, which needs to be paid more attention to.

Norbornadiene homopolymerization and norbornene/norbornadiene/1-octene terpolymerization by ansa-fluorenylamidotitanium-based catalysts

Soluble polyNBD and terpoly(NBD/NB/OC) were obtained in high conversions with ansa-fluorenylamidotitanium-based catalysts.

Methylene blue attenuates renal ischemia-reperfusion injury by negative regulation of NLRP3 signaling pathway

OBJECTIVE

To investigate the effect of methylene blue (MB) on renal ischemia-reperfusion (IR) injury in mice and its possible relevant mechanisms.

MATERIALS AND METHODS

A total of 30 male C57/BL6 mice aged 4 months old were randomly divided into the following three groups: Sham group (n=10), IR group (n=10), and MB group (n=10). Mice in MB group were treated with gavage continuously using methylene blue solution (dosage: 25 mg·kg-1·d-1) until they were 7 months old. Mice in the other two groups were administrated with the same amount of normal saline for gavage. After that, the abdomen of mice in Sham group was opened and closed, and bilateral renal pedicles of mice in IR group and MB group were occluded using a micro-artery clamp for 45 min for modeling. After modeling, the renal tissues and blood samples of mice were taken for detection. The levels of serum creatinine (Scr), blood urea nitrogen (BUN), and malondialdehyde (MDA), and activity of superoxide dismutase (SOD) in mice in each experimental group were detected and statistically analyzed, respectively. The degree of renal tubular necrosis in renal tissues of mice was observed under an optical microscope. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors [interleukin-1β (IL-1β), IL-18, IL-10 and transforming growth factor-β1 (TGF-β1)] in renal tissues of mice in each experimental group, followed by relevant statistical analyses. The expressions of relevant proteins [NACHT, LRR, and PYD domains-containing protein 3 (NLRP3), nuclear factor-κB (NF-κB), caspase-1, pro-IL-1β, and IL-1β] in renal tissues of mice in each experimental group were detected via Western blotting, and the gray value of each band was detected for statistical analysis.

RESULTS

It was found in this experimental study that Scr and BUN levels in MB group were significantly lower than those in IR group, and the differences were statistically significant (p<0.05). Compared with that in IR group, the degree of renal tubular necrosis in MB group was significantly alleviated, and the difference was statistically significant (p<0.05). Compared with those in IR group, the levels of inflammatory factors (IL-1β and IL-18) in MB group were significantly decreased, but the levels of IL-10 and TGF-β1 in MB group were significantly increased, and the differences were statistically significant (p<0.05). Compared with those in IR group, the activity of SOD in MB group was increased significantly, but the level of MDA was decreased, and the differences were statistically significant (p<0.05). The protein expressions of NLRP3, NF-κB, caspase-1, and pro-IL-1β in MB group were decreased compared with those in IR group, but the expression of IL-1β in MB group was increased, and the differences were statistically significant (p<0.05).

CONCLUSIONS

We showed that methylene blue can alleviate the apoptosis and inflammatory response induced by renal IR injury in mice, and its relevant mechanism may be related to the fact that methylene blue can negatively regulate NLRP3 signaling pathway.

Graphite-N Doped Graphene Quantum Dots as Semiconductor Additive in Perovskite Solar Cells

Efficient charge transport is especially important for achieving high performance of perovskite solar cells (PSCs). Here, molecularly designed graphite-nitrogen doped graphene quantum dots (GN-GQDs) act as a functional semiconductor additive in perovskite film. GN-GQDs with abundant N active sites participate in the crystallization of perovskite film and effectively passivate the grain boundary (GB) trap states by Lewis base/acid interaction. Moreover, the semiconductive GN-GQDs at GBs exhibit matched energy structure with the perovskite, which facilitate the charge transport at GBs. GN-GQDs also show n-type dopant property to upshift the Fermi energy level of perovskite films. It largely improves the charge transport in PSCs and reduces the interface recombination at the same time. Profiting from these advantages, inverted planar PSCs with NiO/perovskite/PCBM/BCP structure achieves high efficiency of 19.8% with no hysteresis phenomenon. GN-GQDs modified PSCs also show high stability even without encapsulation, benefiting from the protected GBs and more hydrophobic surface of the modified film. This work highlights a judicious design method of GQDs additive to satisfy efficient and stable PSCs.