Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 54
Filter
1.
Materials (Basel) ; 17(10)2024 May 10.
Article in English | MEDLINE | ID: mdl-38793311

ABSTRACT

Inclusions are one of the important factors affecting the cleanliness of molten steel. The current optimization of inclusion removal methods mainly focuses on promoting inclusions to float to the slag-steel interface so that the inclusions can be absorbed and removed by the refining slag. However, the research on the floating removal of inclusions cannot be carried out directly in the ladle, so methods such as mathematical models and physical models were developed. This article uses silicone oil to simulate the slag layer; polypropylene particles; and aluminum oxide particles to simulate inclusions to establish a water model experiment. By changing the viscosity of silicone oil and the diameter of particles, the factors affecting the movement of inclusions at the slag-steel interface were explored. Based on the water model, a mathematical model of the floating behavior of inclusions at the slag-steel interface was constructed, and parameters such as particle diameter and interfacial tension in the water model experiment were studied by the mathematical model for calculation. Both the mathematical model and the water model experimental results show that after the viscosity of silicone oil increases from 0.048 Pa·s to 0.096 Pa·s, the dimensionless displacement and terminal velocity of the particles decreases. When the diameter of the same particle increases, the dimensionless displacement and terminal velocity increases. The dimensionless displacement of polypropylene particles of the same diameter is larger than that of aluminum oxide particles, and the terminal velocity is smaller than that of aluminum oxide particles. This is attributed to the better overall three-phase wettability of polypropylene particle. When the liquid level increases, the dimensionless displacement and terminal velocity of particles under the same conditions show only slight differences (less than 10%).

2.
Proc Natl Acad Sci U S A ; 121(12): e2316610121, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38489385

ABSTRACT

Many biomolecular condensates, including transcriptional condensates, are formed in elastic mediums. In this work, we study the nonequilibrium condensate dynamics in a chromatin-like environment modeled as a heterogeneous elastic medium. We demonstrate that the ripening process in such an elastic medium exhibits a temporal power-law scaling of the average condensate radius, depending on the local stiffness distribution and different from Ostwald ripening. Moreover, we incorporate an active process to model the dissolution of transcriptional condensates upon RNA accumulation. Intriguingly, three types of kinetics of condensate growth emerge, corresponding to constitutively expressed, transcriptional-bursting, and silenced genes. Furthermore, the simulated burst frequency decreases exponentially with the local stiffness, through which we infer a lognormal distribution of local stiffness in living cells using the transcriptome-wide distribution of burst frequency. Under the inferred stiffness distribution, the simulated distributions of bursting kinetic parameters agree reasonably well with the experimental data. Our findings reveal the interplay between biomolecular condensates and elastic mediums, yielding far-reaching implications for gene expression.


Subject(s)
Biomolecular Condensates , Nuclear Bodies , Chromatin , Elasticity , Kinetics
3.
J Phys Chem Lett ; 15(6): 1726-1733, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38323848

ABSTRACT

Quantum-dot light-emitting diodes (QLEDs) with memory capability can provide multifunctional integration properties in on-chip and intelligent electronic applications. Herein, memory properties are achieved by inserting a tungsten oxide (WOx) film between the ZnO electron-transporting layer and cathode. Pentavalent tungsten ions (W5+) in this nonstoichiometric WOx film can be oxidized to W6+ by storing holes, inducing significant electrons in the adjacent ZnO layer. Hole storage in the WOx layer suppresses electron injection into the quantum dot emissive layer, hence reducing electroluminescence intensity on the onset stage of the QLEDs. This operation-history correlation for the electroluminescence intensity means a memory behavior for the QLEDs. Furthermore, the power efficiency of the devices is greatly improved after inserting the WOx layer due to electrical field-dependent self-adaptive electron injection into the quantum dots (QDs). We anticipate this type of QLEDs have potential applications in on-chip integration applications, such as the optical computing field and storage.

4.
Environ Sci Ecotechnol ; 20: 100369, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38318213

ABSTRACT

•Dumping of Fukushima's radioactive wastewater raises marine food web concern.•Tritium seems to be the most problematic compound.•Long-lived radioisotopes Biomagnify up to 50,000 folds in marine fish species.•This threatens fragile deep-sea ecosystems requiring immediate action.•Empowered Routine monitoring is crucial to maintain planetary health.

5.
BMC Musculoskelet Disord ; 25(1): 101, 2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38287387

ABSTRACT

BACKGROUND: The hip joint capsule is an essential component of hip joint function and stability, and its thickness is closely associated with certain medical conditions, surgical outcomes, and rehabilitation treatments. Currently, in clinical practice, hip joint capsule thickness is predominantly measured using magnetic resonance imaging (MRI), with limited utilization of ultrasound examinations for this purpose. METHODS: We retrospectively evaluated patients who visited our Sports Medicine Department between February 2017 and March 2023 and underwent both hip joint MRI and ultrasound imaging on the same side. All patients had undergone preoperative hip joint MRI and ultrasound examinations, with the time gap between the two examinations not exceeding three months. Measurements of hip joint capsule thickness were taken on both MRI and ultrasound images for the same patients to analyze their consistency. Additionally, we measured the alpha angle, lateral center-edge angle, acetabular anteversion angle, and femoral anteversion angle of the patients' hip joints and analyzed their correlation with hip joint capsule thickness measure by ultrasound. RESULTS: A total of 307 patients were included in this study, with hip joint capsule thickness measured by MRI and ultrasound being 5.0 ± 1.2 mm and 5.0 ± 1.5 mm, respectively. The Bland-Altman analysis demonstrates good agreement or consistency. The paired t-test resulted in a p-value of 0.708, indicating no significant statistical difference between the two methods. The correlation analysis between acetabular anteversion angle and ultrasound-measured capsule thickness yielded a p-value of 0.043, indicating acetabular anteversion angle and capsular thickness may have negative correlation. CONCLUSIONS: The measurements of joint capsule thickness obtained through ultrasound and MRI showed good consistency, suggesting that ultrasound can be used in clinical practice as a replacement for MRI in measuring hip joint capsule thickness. There was a significant correlation between acetabular anteversion angle and hip joint capsule thickness, indicating potential for further research in this area.


Subject(s)
Acetabulum , Hip Joint , Humans , Retrospective Studies , Hip Joint/surgery , Acetabulum/surgery , Joint Capsule/diagnostic imaging , Ultrasonography
6.
Eco Environ Health ; 2(3): 92-94, 2023 Sep.
Article in English | MEDLINE | ID: mdl-38074991

ABSTRACT

Image 1.

7.
JAMA Surg ; 158(12): 1245-1253, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37878305

ABSTRACT

Importance: The safety and efficacy of laparoscopic pancreaticoduodenectomy for pancreatic ductal adenocarcinoma remain controversial. Objective: To compare laparoscopic and open pancreaticoduodenectomy performed by experienced surgeons in patients with pancreatic ductal adenocarcinoma. Design, Setting, and Participants: This was a noninferiority, open-label randomized clinical trial between September 20, 2019 and March 20, 2022, at 10 hospitals in China. A total of 412 adult patients were assessed for eligibility; 200 patients with histologically confirmed or clinically diagnosed pancreatic ductal adenocarcinoma who were eligible to undergo pancreaticoduodenectomy were enrolled. Study recruitment is complete, and follow-up is ongoing. This article reports prespecified early safety results from the trial. Interventions: Participants were randomized in a 1:1 ratio to undergo either laparoscopic or open pancreaticoduodenectomy, to be performed by experienced surgeons who had already performed at least 104 laparoscopic pancreaticoduodenectomy operations. Main Outcomes and Measures: The primary end point is 5-year overall survival, but the data for this end point are not yet mature; thus, secondary short-term outcomes, including operative findings, complications, mortality, and oncological results are reported here. The outcomes were analyzed according to a modified intention-to-treat and per-protocol principle. Results: Among 412 patients for eligibility, 200 patients were enrolled and randomly assigned 1:1 to have laparoscopic pancreaticoduodenectomy or open pancreaticoduodenectomy. The mean (SD) age was 61.3 (9.3) years, and 78 participants (39%) were female. Laparoscopic procedures had longer operative times (median [IQR], 330.0 [287.5-405.0] minutes vs 297.0 [245.0-340.0] minutes; P < .001). Patients in the laparoscopic group lost less blood than those in the open group (median [IQR], 145.0 [100.0-200.0] mL vs 200.0 [100.0-425.0] mL; P = .02). Ninety-day mortality occurred in 2 of 100 patients in the laparoscopic group and 0 of 100 patients in the open group. There was no difference in the rates of complications of the Clavien-Dindo grades III-IV (n = 17 [17.0%] vs n = 23 [23.0%]; P = .29), comprehensive complication index (median [IQR], 0.0 [0.0-22.6] vs 8.7 [0.0-26.2]; P = .79) or median (IQR) postoperative length of stay (14.0 [11.0-17.0] days vs 14.0 [12.0-18.5] days; P = .37) between the 2 groups. Conclusions and Relevance: Laparoscopic pancreaticoduodenectomy performed by experienced surgeons in high-volume specialized institutions resulted in similar short-term outcomes compared with open pancreaticoduodenectomy among patients with pancreatic ductal adenocarcinoma. Trial Registration: ClinicalTrials.gov Identifier: NCT03785743.


Subject(s)
Carcinoma, Pancreatic Ductal , Laparoscopy , Pancreatic Neoplasms , Adult , Humans , Female , Middle Aged , Male , Pancreaticoduodenectomy/adverse effects , Postoperative Complications/etiology , Pancreatic Neoplasms/surgery , Laparoscopy/methods , Carcinoma, Pancreatic Ductal/surgery
8.
J Orthop Surg Res ; 18(1): 565, 2023 Aug 03.
Article in English | MEDLINE | ID: mdl-37537643

ABSTRACT

BACKGROUND: The association between chronic anterior cruciate ligament (ACL) injury and inferior postoperative outcomes following ACL reconstruction (ACLR) has been highlighted in the literature. However, the inclusion of postoperative radiological assessments in previous studies has been limited. The aim of this study is to investigate whether chronic ACL injury is associated with an inferior tibiofemoral position measured on magnetic resonance (MR) images after primary ACLR. METHODS: A total of 62 patients that underwent primary ACLR were included in this study based on the time from injury to surgery, namely the acute ACL-injured group (within 6 weeks) and the chronic ACL-injured group (more than 1 year) and were matched 1:1 according to sex, age (± 2 years), and time from surgery to follow-up (± 3 months). Patient demographics, surgical records and follow-up data were retrieved and analyzed. The altered tibiofemoral position was measured quantitatively on preoperative and at least 1-year postoperative MR images and compared between the two groups, including the lateral, medial and global anterior tibial subluxation (LATS, MATS and GATS) and internal rotational tibial subluxation (IRTS). RESULTS: No significant differences in preoperative LATS, MATS, GATS or IRTS were identified between the acute and chronic ACL-injured groups. The chronic ACL-injured patients showed significantly increased postoperative MATS (p = 0.001) and GATS (p = 0.012), while no significant difference was identified in postoperative LATS or IRTS. Multivariate linear regression analyses showed that chronic ACL injury resulted in an estimated increase of 2.0 mm in postoperative MATS (p = 0.012) and 1.9 mm in postoperative GATS (p = 0.040). A significant improvement in postoperative LATS was observed in the acute ACL-injured group (p = 0.044) compared to preoperative LATS, while no improvements in these MRI measurements were observed in the chronic ACL-injured group. CONCLUSION: Chronic ACL-injured patients showed increased MATS and GATS measured on 1-year postoperative MR images after primary single-bundle ACL reconstruction, while no difference was identified in rotational tibiofemoral position. The acute ACL-injured group demonstrated a significant improvement in postoperative LATS, whereas no improvements were observed in the chronic ACL-injured group. Level of evidence Level III.


Subject(s)
Anterior Cruciate Ligament Injuries , Joint Dislocations , Humans , Anterior Cruciate Ligament/surgery , Anterior Cruciate Ligament Injuries/diagnostic imaging , Anterior Cruciate Ligament Injuries/surgery , Knee Joint/surgery , Tibia/diagnostic imaging , Tibia/surgery , Magnetic Resonance Imaging , Retrospective Studies
9.
Environ Microbiol Rep ; 15(6): 557-567, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37594161

ABSTRACT

Advances in many isolation studies have revealed that pure Dehalococcoides grow stably, although the large-scale pure cultivation of Dehalococcoides has yet to be established. In this study, 7 L-culturing of Dehalococcoides mccartyi strain NIT01 was first performed using vessels made of glass and stainless alloy SUS304. All batches cultured in the glass vessel successfully dechlorinated >95% of 1 mM trichloroethene (TCE) to ethene (ETH), whereas only 5 out of 13 batches cultured in the SUS304 vessel did the same. The difference in dechlorination efficiency suggested the possible inhibition of dechlorination by SUS304. Also, the strain NIT01 showed long delays in dechlorination with pieces of SUS316, steel, and a repeatedly used SUS304, but not with titanium. The repeatedly used SUS304 cracked and increased the Fe2+ concentration to ≥76 µM. Dechlorination by this strain was also inhibited with ≥1000 µM Fe2+ and ≥23 µM Cr3+ but not with ≤100 µM Ni2+ , suggesting that Cr3+ eluted from solid stainless alloys inhibited the dechlorination. Culturing in a titanium vessel instead of a stainless alloy showed the complete dechlorination of 1 mM TCE within 12-28 days with a growth yield of 2.7 × 107 cells/µmol-released Cl- , even after repeating use of the vessels six times.


Subject(s)
Chloroflexi , Trichloroethylene , Biodegradation, Environmental , Titanium , Alloys , Halogenation
10.
J Hazard Mater ; 459: 132251, 2023 10 05.
Article in English | MEDLINE | ID: mdl-37591166

ABSTRACT

Dehalococcoides is a functional microorganism that completely dechlorinates trichloroethene (TCE). Augmentation with pure Dehalococcoides is important for reducing environmental disturbances that accompany bioaugmentation. However, the applicability of Dehalococcoides-bioaugmentation to contaminated soils is unclear. In this study, seven low-carbon energy sources (methanol, formate, acetate, ethanol, lactate, citrate, and benzoate) were used as electron donors for Dehalococcides to evaluate its applicability in remediating TCE-contaminated soils. Soil microcosms supplemented with ethanol, formate, or lactate showed relatively high dechlorination activity within 111-180 days. The functional gene profiles predicted by PICRUSt2 from 16 S rRNA gene sequences were similar in the proportions of dehydrogenases, which initiate electron donor oxidation, in all soils and did not seem to reflect Dehalococcoides-bioaugmentation applicability. Soils with higher organic matter content (>3.2%; dry weight base) and protein concentration (>1.6 µg/mL) supported complete dechlorination. These results suggest that organic matter and nutrient availability mainly affect successful TCE dechlorination in Dehalococcoides-augmented soils. The study offers significant experimental support for comprehending the suitability of low-carbon energy sources in successful bioaugmentation, aiming to mitigate environmental disturbances associated with the process.


Subject(s)
Dehalococcoides , Lactic Acid , Carbon , Ethanol , Formates , Nutrients
11.
Microorganisms ; 11(2)2023 Jan 30.
Article in English | MEDLINE | ID: mdl-36838314

ABSTRACT

Graphene oxide (GO), a chemically oxidized sheet of graphite, has been used as a conductive carbon carrier of microbes to boost various bioelectrochemical reactions. However, the types of microbes that can reduce GO have rarely been investigated. In this study, a strain of GO-reducing bacteria, named NIT-SL11, which was obtained from a hydrogel of microbially reduced GO and anaerobic sludge that converts sewage to electricity, was phylogenically identified as a novel strain of Geotalea uraniireducens. Considering the current lack of information on the electrogenic ability of the bacterium and its physicochemical and chemotaxonomic characteristics, the polyphasic characterization of the Geotalea uraniireducens strain NIT-SL11 was performed. NIT-SL11 utilized various organic acids, such as lactate, benzoate, and formate, as electron donors and exhibited respiration using GO, electrodes, fumarate, and malate. The strain contained C16:1ω7c and C16:0 as the major fatty acids and MK-8 and 9 as the major respiratory quinones. The complete genome of NIT-SL11 was 4.7 Mbp in size with a G+C content of 60.9%, and it encoded 80 putative c-type cytochromes and 23 type IV pili-related proteins. The possible extracellular electron transfer (EET) pathways of the strain were the porin-cytochrome (Pcc) EET pathway and type IV pili-based pathway.

12.
Asian J Surg ; 46(1): 306-313, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35431124

ABSTRACT

PURPOSE: To study the outcomes of laparoscopic pancreaticoduodenectomy (LPD) using a modified technique. METHODS: Our center used priority approach of uncinate process and artery in the pancreatectomy and duct to mucosa pancreaticojejunostomy with a single stitch in the pancreaticojejunostomy. Herein, we retrospectively reviewed 346 cases of LPD using modified techniques. Basic characteristics, preoperative outcomes, factors associated with unfavorable postoperative outcome, and mortality of patients undergoing LPD were collected and analyzed. RESULTS: The average operative time was 259.31 (35-425) min. The mean duration of pancreaticojejunostomy anastomosis was 31.97 (16-90) min. The mean intraoperative blood loss was 101.76 (0-1200) ml by estimation. Postoperative complications included 14 cases (4.1%) of bile leakage, 9 cases (2.6%) of delayed gastric emptying, 26 cases (7.5%) of postoperative bleeding, 34 cases (9.9%) of organ space infection, 17 cases (4.9%) of pulmonary infection, and 50 cases (14.5%) of POPF. Three factors including postoperative bleeding (OR = 3.502; P = 0.033), positive lymph node (OR = 3.296; P < 0.001), and postoperative chemotherapy (OR = 0.241; P = 0.008) were significantly associated with death of LPD. CONCLUSIONS: The modified technique for LPD presents safety and reliability. Postoperative bleeding and positive lymph node may be associated with worse overall survival, and postoperative chemotherapy may be associated with better overall survival.


Subject(s)
Laparoscopy , Pancreaticoduodenectomy , Humans , Pancreaticoduodenectomy/methods , Pancreatectomy , Retrospective Studies , Reproducibility of Results , Pancreaticojejunostomy/methods , Laparoscopy/methods , Anastomosis, Surgical/methods , Postoperative Complications/epidemiology , Postoperative Hemorrhage/epidemiology , Pancreatic Fistula/etiology
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 286: 122021, 2023 Feb 05.
Article in English | MEDLINE | ID: mdl-36283209

ABSTRACT

A novel fluorescent sensor was developed in this study based on glutathione-functionalized graphene quantum dots (GQDs@GSH) to detect organophosphorus pesticide residues in Radix Angelica Sinensis. GQDs@GSH was synthesized by a one-step pyrolysis method with a fluorescence quantum yield as high as 33.9% and its structure was characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. GQDs@GSH exhibited excellent fluorescence property showing strong blue fluorescence under UV irradiation. The fluorescence of GQDs@GSH could be quenched by Fe3+ by electron transfer and the quenched fluorescence could be recovered due to the strong chelating and reducing ability of phytic acid (PA). Under the catalyzation of acetylcholinesterase (AChE) and choline oxidase (ChOx), acetylcholine (ACh) could be decomposed to H2O2, which could further oxidize Fe2+ to Fe3+ thus quenching the fluorescence of GQDs@GSH once again. Coumaphos, a kind of organophosphorus pesticide, could inhibit AChE activity, thus making the quenched fluorescence turn on again. Several parameters influencing the fluorescence response such as Fe3+, PA, ACh and coumaphos concentration, pH value and reaction time were optimized. Based on such a fluorescence "off-on-off-on" ngkmechanism, GQDs@GSH was successfully applied to the detection of coumaphos in Radix Angelica Sinensis. A good linear relationship between the fluorescence intensity and coumaphos concentration was obtained in the range of 0.1-10.0 µmol·L-1. By a standard addition method, the recoveries were measured to be 101.44-117.90% with RSDs lower than 1.98%. The biosensor system is simple, sensitive and accurate. It has a good application prospect in the detection of organophosphorus pesticide residues in traditional Chinese medicine and agricultural products, and also expanded the application scope for glutathione as a highly selective biological molecule.


Subject(s)
Angelica sinensis , Graphite , Pesticide Residues , Pesticides , Quantum Dots , Quantum Dots/chemistry , Graphite/chemistry , Fluorescent Dyes/chemistry , Organophosphorus Compounds , Acetylcholinesterase , Hydrogen Peroxide , Coumaphos , Glutathione/chemistry
14.
Biosens Bioelectron ; 218: 114754, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36206670

ABSTRACT

Conductive carbons can boost anaerobic microbial metabolism by assisting extracellular electron transfer (EET), and their chemistry affects microbial metabolism. Graphene oxide (GO), a chemically oxidized sheet of graphite, has been used in various bioelectrochemical systems, although its mechanism is rarely understood. This study revealed specific metabolic responses to reduced GO (rGO) in an electrogenic strain R4 of Citrifermentans bremense, recently renamed from "Geobacter bremensis," in comparison to that with graphite felt (GF). Specifically, the change in growth from planktonic cells to biofilm with an enlarged outer membrane. The mRNA profile supported the fact that rGO upregulated the 14 genes related to the exopolysaccharides (EPS) secretion and biofilm formation, which is more than that in GF (4 genes). While GF upregulated the 35 genes involved in cell motility, which is more than that in rGO (8 genes). The heme protein profile suggested that both carbons induced similar EET pathways involving OmcA/MtrC and OmcS; however, GO specifically induced PilQ. These findings show that the chemistry of conductive carbon differentiates metabolism, especially affecting cellular morphology or living form, rather than electron transfer metabolism.


Subject(s)
Biosensing Techniques , Graphite , Hemeproteins , Carbon , RNA, Messenger
15.
Front Mol Biosci ; 9: 980841, 2022.
Article in English | MEDLINE | ID: mdl-36188229

ABSTRACT

Objective: Breast cancer (BC) is becoming the leading cause of cancer-related death in women all over the word. Identification of diagnostic biomarkers for early detection of BC is one of the most effective ways to reduce the mortality. Methods: Plasma samples from BC patients (n = 120) and normal controls (n = 50) were collected to determine the differentially expressed circulating miRNAs in BC patients. Binary logistic regression was applied to develop miRNA diagnostic models. Receiver operating characteristic (ROC) curves were applied to calculate the area under the curve (AUC). MMTV-PYMT mammary tumor mice were used to validate the expression change of those circulating miRNAs. Plasma samples from patients with other tumor types were collected to determine the specificity of the model in diagnosis of BC. Results: In the screening phase, 5 circulating miRNAs (miR-16, miR-17, miR-19b, miR-27a, and miR-106a) were identified as the most significantly upregulated miRNAs in plasma of BC patients. In consistence, the 5 miRNAs showed upregulation in the circulation of additional 80 BC patients in a tumor stage-dependent manner. Application of a tumor-burden mice model further confirmed upregulation of the 5 miRNAs in circulation. Based on these data, five models with diagnostic potential of BC were developed. Among the 5 miRNAs, miR-19b ranked at the top position with the highest specificity and the biggest contribution. In combination with miR-16 and miR-106a, a miR-19b-based 3-circulating miRNA model was selected as the best for further validation. Taken the samples together, the model showed 92% of sensitivity and 90% of specificity in diagnosis of BC. In addition, three other tumor types including prostate cancer, thyroid cancer and colorectal cancer further verified the specificity of the BC diagnostic model. Conclusion: The current study developed a miR-19b-based 3-miRNA model holding potential for diagnosis of BC using blood samples.

16.
ACS Omega ; 7(32): 28030-28040, 2022 Aug 16.
Article in English | MEDLINE | ID: mdl-35990432

ABSTRACT

Thermally rectifying materials would have important implications for thermal management, thermal circuits, and the field of phononics in general. Graphene-based nanostructures have very high intrinsic thermal conductance, but they normally display no thermal rectification effects. The present study relates to a thermally rectifying material and, more particularly, to a graphene-based nanomaterial for controlling heat flux and the associated method determining the rectification coefficient. Thermal rectifiers using a graphene-based nanostructure as thermal conductors were designed. Vacancy defects were introduced into one end of the nanostructure to produce an axially non-uniform mass distribution. Modified Monte Carlo methods were used to investigate the effects of defect size and shape, vacancy concentration, and ribbon length on the thermal rectification properties. Anharmonic lattice dynamics calculations were carried out to obtain the frequency-dependent phonon properties. The results indicated that the nanoscale system conducts heat asymmetrically, with a maximum available rectification coefficient of about 70%. Thermal rectification has been achieved, and the difference in temperature dependence of thermal conductivity is responsible for the phenomenon. Defects can be tailored to modulate the temperature dependence of thermal conductivity. The power-law exponent can be negative or positive, depending upon the ribbon length and vacancy concentration. A computational method has been developed, whereby the numerous variables used to determine the rectification coefficient can be summarized by two parameters: the power-law exponent and the thermal resistance ratio. Accordingly, the rectification coefficient can be obtained by solving a simple algebraic expression. There are several structure factors that cause noticeable effects on the thermal rectification properties. Defect size, vacancy concentration, and ribbon length can affect the thermal conductance of the nanostructure symmetrically and significantly. Graphene-based nanostructure thermal rectifiers can be arranged in an array so as to provide thermal rectification on a macroscopic scale.

17.
Chemosphere ; 307(Pt 4): 136080, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35988762

ABSTRACT

Various substrates have been used to stimulate habitat microbes in chloroethene-contaminated groundwater, however, the specific efficiency and minimum growth of microbes have rarely been studied. This study investigated the effects of seven substrates on trichloroethene (TCE) dechlorination by augmentation of groundwater with Dehalococcoides mccartyi NIT01 and its contribution to the microbial community. Three out of eight test groups completed dechlorination of 1 mM TCE-to-ethene in varying durations; groundwater supplemented with formate (FOR) required 78 days, whereas the microcosms with lactate (LAC) and citrate (CIT) required approximately twice as long (143 days). The calculated efficiency of how much produced H2 was used in dechlorination indicated a higher efficiency in FOR (36%) compared with LAC (1.9%) or CIT (2.9%). FOR showed lower microbial growth (3.4 × 105 copies/mL) than LAC (1.5 × 106) or CIT (4.4 × 106), and maintained a higher Shannon diversity index (5.65) than LAC (4.97) and CIT (4.30). The rapid and higher H2 transfer efficiency with lower bacterial growth by using formate was attributed to the slightly positive Gibbs free energy identified in H2 production requiring a H2-utilizer, lower carbon in the molecule, and adaptation to metabolic potential of the original groundwater microbiome. Formate is, therefore, a promising electron donor for rapid Dehalococcoides-augmented remediation with minimum bacterial growth. Sequential transferring of the FOR culture successfully maintained TCE-to-ethene dechlorination activity and enriched the members of genera Dehalococcoides (33%), Methanosphaerula (23%), Rectinema (13%), and Desulfitobacterium (5.6%). This suggests that formate is transferred to H2 and acetate, and provided to Dehalococcoides.


Subject(s)
Chloroflexi , Groundwater , Microbiota , Trichloroethylene , Biodegradation, Environmental , Carbon/metabolism , Chloroflexi/metabolism , Citrates , Dehalococcoides , Electrons , Ethylenes , Formates/metabolism , Groundwater/microbiology , Lactates/metabolism , RNA, Ribosomal, 16S/metabolism , Trichloroethylene/chemistry
18.
Polymers (Basel) ; 14(11)2022 May 26.
Article in English | MEDLINE | ID: mdl-35683832

ABSTRACT

The greenhouse effect and plastic pollution caused by the accumulation of plastics have led to a global concern for environmental protection, as well as the development and application of biodegradable materials. Polypropylene carbonate (PPC) is a biodegradable polymer with the function of "carbon sequestration", which has the potential to mitigate the greenhouse effect and the plastic crisis. It has the advantages of good ductility, oxygen barrier and biocompatibility. However, the mechanical and thermal properties of PPC are poor, especially the low thermal degradation temperature, which limits its industrial use. In order to overcome this problem, PPC can be modified using environmentally friendly materials, which can also reduce the cost of PPC-based products to a certain extent and enhance their competitiveness in terms of improving their mechanical and thermal properties. In this paper, we present different perspectives on the synthesis, properties, degradation, modification and post-modification applications of PPC. The modification part mainly introduces the influence of inorganic materials, natural polymer materials and degradable polymers on the performance of PPC. It is hoped that this work will serve as a reference for the early promotion of PPC.

19.
Diagn Pathol ; 17(1): 49, 2022 Jun 02.
Article in English | MEDLINE | ID: mdl-35655305

ABSTRACT

BACKGROUND: Synovial sarcoma is a soft tissue sarcoma of temporarily unknown histologic origin with the ability for biphasic differentiation, occurring mostly in the vicinity of large joints of the extremities. Synovial sarcoma that originates in the liver is extremely rare. Only 7 cases have been reported in the domestic and international literature. CASE PRESENTATION: We report an 11-year-old female patient who underwent partial hepatectomy for a liver mass. Microscopically, she was diagnosed with hepatic biphasic synovial sarcoma. Cytogenetic examination revealed the fusion gene SS18-SSX1 (+), which confirmed the diagnosis. CONCLUSION: Synovial sarcoma of the liver is a rare malignancy that is difficult to diagnose. Confirmation of diagnosis is based on histopathological assessment combined with immunohistochemical staining and, if necessary, cytogenetic aids.


Subject(s)
Liver Neoplasms , Sarcoma, Synovial , Soft Tissue Neoplasms , Child , Female , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/genetics , Oncogene Proteins, Fusion/genetics , Sarcoma, Synovial/diagnosis , Sarcoma, Synovial/genetics , Sarcoma, Synovial/pathology
20.
ACS Omega ; 7(23): 20186-20194, 2022 Jun 14.
Article in English | MEDLINE | ID: mdl-35722022

ABSTRACT

Understanding the effect of phonon scattering is of primary significance in the study of the thermal transport properties of graphene. While phonon scattering negatively affects the thermal conductivity, the exact effect of microscopic phonon scattering is still poorly understood when full phonon dispersions are taken into account. The heat transport properties of graphene ribbons were investigated theoretically by taking into account different polarization branches with different frequencies in order to understand the physical mechanism of the thermal transport phenomenon at the nanoscale. The effects of grain size, chiral angle, Grüneisen anharmonicity parameter, specularity parameter, and mass-fluctuation-scattering parameter were evaluated, taking into account of the restrictions imposed by boundary, Umklapp, and isotope scattering mechanisms. The contribution from each phonon branch was estimated, and the anisotropic coefficients were determined accordingly. The results indicated that the graphene ribbons are very efficient at conducting heat in all the cases studied. All the acoustical branches contribute significantly to the heat transport properties, and the temperature strongly affects the relative contribution of the phonon branches. The lattice thermal conductivity varies periodically with the chiral angle. The maximum thermal conductivity is achieved in the zigzag direction, and the minimum thermal conductivity is obtained in the armchair direction. The lattice thermal conductivity and anisotropic coefficient depend heavily upon the roughness of the edges and the width of the ribbons. The specularity parameter and mass-fluctuation-scattering parameter significantly affect the lattice thermal conductivity, and the effect arising from isotope scattering is significant in the context of natural isotopic abundance. The dependence of the Grüneisen anharmonicity parameter on phonon branches must be taken into account when making predictions. The results have significant implications for the understanding of the relations between phonon scattering and thermal properties.

SELECTION OF CITATIONS
SEARCH DETAIL
...