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1.
J Mol Model ; 30(7): 222, 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38907083

ABSTRACT

CONTEXT: The development of efficient solar energy conversion technologies is crucial for addressing global energy challenges and reducing reliance on fossil fuels. Platinum(II) complexes are promising materials for photovoltaic applications due to their strong light absorption and long-lived excited states. However, their narrow absorption in the visible spectrum and stability issues limit their performance. Combining platinum(II) complexes with graphene quantum dots (GQDs) can enhance photovoltaic performance by leveraging the complementary light harvesting and charge transfer characteristics of the two components. This study utilizes density functional theory (DFT) calculations to explore their electronic structures, charge transfer dynamics, and photoelectric performance. Specifically, it investigates the effects of incorporating different substituents, either electron-donating or electron-withdrawing, onto the fluorene motif of the Pt(II) complex. The findings reveal that combining GQDs with Pt(II) complexes extends light absorption into the UV range, enabling comprehensive solar utilization. Upon photoexcitation, electrons migrate between the GQD conduction band and the Pt(II) complex, stabilizing charges and enhancing extraction. Substituents significantly influence charge transfer dynamics: electron-withdrawing groups promote transfer to the GQD, while electron-donating groups encourage charge separation and delocalization. Nanocomposites featuring electron-donating substituents achieve the highest energy conversion efficiencies, with GQD@Pt(II)-NPh2 reaching 24.6%. This is attributed to improved light harvesting, efficient charge injection, and reduced recombination. These insights guide the rational design of GQD-Pt(II) nanocomposites, optimizing charge separation and transfer processes for enhanced photovoltaic performance. The computational approach employed here provides a robust tool for developing advanced materials in renewable energy technologies. METHODS: The computational studies reported in this work were performed using the DFT approach, specifically employing the hybrid functional PBE0. The PBE0 functional's accuracy in describing electronic structures and excited-state properties is essential for understanding charge transfer processes, photoabsorption, and emission characteristics in metal-organic complexes. Geometry optimizations and time-dependent DFT (TD-DFT) calculations were carried out to investigate the properties of the nanocomposites. The effects of solvents were replicated using the conductor-like polarizable continuum model (CPCM). The charge transfer length (ΔL) and interfragment charge transfer (ΔQ) were calculated using the Multiwfn software package, and all calculations were performed using the BDF software package.

2.
Nanotechnology ; 35(17)2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38334144

ABSTRACT

Boron nitride quantum dots (BNQDs) have emerged as promising photocatalysts due to their excellent physicochemical properties. This study investigates strategies to enhance the photocatalytic performance of BNQDs through sulfur-doping (S-BNQDs) and edge-functionalization with ligands (urea, thiourea, p-phenyl-enediamine (PPD)). To analyze the geometry, electronic structure, optical absorption, charge transfer, and photocatalytic parameters of pristine and functionalized S-BNQDs, we performed density functional theory calculations. The results showed that S-doping and ligand functionalization tune the bandgap, band energies, and introduce mid-gap states to facilitate light absorption, charge separation, and optimized energetics for photocatalytic redox reactions. Notably, the PPD ligand induced the most substantial bandgap narrowing and absorption edge red-shift by over 1 electron volt (eV) compared to pristine S-BNQD, significantly expanding light harvesting. Additionally, urea and PPD functionalization increased the charge transfer length by up to 2.5 times, effectively reducing recombination. On the other hand, thiourea functionalization yielded the most favorable electron injection energetics. The energy conversion efficiency followed the order: PPD (15.0%) > thiourea (12.0%) > urea (11.0%) > pristine (10.0%). Moreover, urea functionalization maximized the first-order hyperpolarizability, enhancing light absorption. These findings provide valuable insights into tailoring S-BNQDs through strategic doping and functionalization to develop highly efficient, customized photocatalysts for sustainable applications.

3.
J Mol Model ; 30(1): 6, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38091121

ABSTRACT

CONTEXT: Boron nitride quantum dots (BNQDs) are emerging as promising multifunctional nanomaterials for renewable energy and optoelectronics owing to their versatile properties. However, rational design principles to tailor their photoelectric and photoluminescent capabilities remain scarce. This study employs density functional theory (DFT) to provide fundamental insights into using urea, thiourea, and PPD ligands to modulate the bandgap, charge transfer dynamics, and recombination processes of BNQDs. Modeling explains that incorporating specific ligands enables visible light absorption, spatial charge separation, continuous photocatalytic cycling, and high quantum yields in BNQDs. The structure-property relationships established pave the way for targeted synthesis of high-performance BNQD photocatalysts and light emitters. METHODS: This investigation utilized density functional theory (DFT) with the B3LYP functional and 6-31G(d,p) basis set to optimize the geometries of pristine and ligand-functionalized boron nitride quantum dots (BNQDs). The absorption spectra were generated using time-dependent DFT (TDDFT). A Ti38O76 cluster modeled the TiO2 substrate. The cpcm solvation model in Gaussian 09 defined the toluene solvent. Cohesive energies, charge transfer lengths, recombination rates, and conversion efficiencies were calculated to establish structure-property relationships. Multiwfn analyzed the charge densities. The modeling provides insights into tuning BNQD photocatalytic and photoluminescent properties using specific ligands.

4.
BMC Cancer ; 23(1): 1109, 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37964212

ABSTRACT

BACKGROUND: Current chemotherapy-induced peripheral neuropathy (CIPN) assessment tools mostly have poor sensitivity and weak anti-interference, so that it is sometimes difficult to provide substantive guidance for clinical intervention. This study aimed to develop an assessment tool dedicated for oxaliplatin to address these limitations. METHODS: This study screened 445 OIPN-related literatures for producing a symptom list, and developed the questionnaire module through expert supplement, item generation, content correlation analysis, pre-testing, and item improvement. The validation phase used a Chinese population-based prospective cohort study from June 2021 to July 2022. Patients were requested to complete the tested questionnaire, QLQ-CIPN20 and the CTCAE grading one day before cycles 2-6 of chemotherapy. Cronbach's α coefficient and intraclass correlation coefficient (ICC) were calculated for the internal consistency and stability analysis, respectively. Exploratory factor analysis was conducted to investigate the construct validity. The correlations among the tested questionnaire, QLQ-CIPN20 and CTCAE were compared for the criterion validity analysis. Wilcoxon signed-rank sum test was utilized to compare the sensitivity between the tested questionnaire and QLQ-CIPN20. RESULT: A 20-item CIPN assessment tool named chemotherapy-induced peripheral neuropathy integrated assessment - oxaliplatin subscale (CIPNIA-OS) was developed. The validation phase included 186 patients. Cronbach's α coefficient of CIPNIA-OS was 0.764 (> 0.7), and ICC was 0.997 (between 0.9 and 1). The structure of CIPNIA-OS containing seven factors was examined. The correlation coefficient between CIPNIA-OS and CTCAE was 0.661 (95%CI 0.623 to 0.695), which was significantly higher than that between QLQ-CIPN20 and CTCAE (0.417, 95%CI 0.363 to 0.469, p < 0.01). Besides, the total score of CIPNIA-OS was mostly higher than QLQ-CIPN20, with an average difference of 2.189 (CI 95% 2.056 to 2.322), and the difference gradually expanded with the progress of chemotherapy (p < 0.05). CONCLUSION: This study developed an original CIPN questionnaire which was dedicated for OIPN assessment. It was a comprehensive tool that covered acute OIPN symptoms and integrated features from several proven CIPN assessment tools. The validation results supported that CIPNIA-OS had satisfactory reliability, stability, construct, criterion validity, and was more accuracy and sensitive than QLQ-CIPN20 in the evaluation of OIPN.


Subject(s)
Antineoplastic Agents , Neoplasms , Peripheral Nervous System Diseases , Humans , Oxaliplatin/adverse effects , Antineoplastic Agents/adverse effects , Neoplasms/drug therapy , Reproducibility of Results , Prospective Studies , Quality of Life , Peripheral Nervous System Diseases/chemically induced , Peripheral Nervous System Diseases/diagnosis , Peripheral Nervous System Diseases/drug therapy
5.
Chembiochem ; 24(22): e202300391, 2023 11 16.
Article in English | MEDLINE | ID: mdl-37718314

ABSTRACT

We report a fluorescent dye TM by incorporating the tetraphenylethylene (TPE) and cholesterol components into perylene bisimides (PBI) derivative. Fluorescence emission spectrum shows that the dye has stable red emission and aggregation-induced emission (AIE) characteristics. The incorporation of cholesterol components triggers TM to show induced chirality through supramolecular self-assembly. The cRGD-functionalized nanoparticles were prepared by encapsulating fluorescent dyes with amphiphilic polymer matrix. The functionalized fluorescent organic nanoparticles exhibit excellent biocompatibility, large Stokes' shift and good photostability, which make them effective fluorescent probes for targeting cancer cells with high fluorescence contrast.


Subject(s)
Nanoparticles , Neoplasms , Fluorescent Dyes/pharmacology , Polymers , Diagnostic Imaging , Cholesterol , Neoplasms/diagnostic imaging
6.
Photochem Photobiol Sci ; 22(11): 2621-2634, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37718379

ABSTRACT

Using density functional theory (DFT), this study investigates the photoelectric performance of nanocomposites formed by coupling graphene quantum dots (GQDs) with Ir(III) complexes. The goal is to evaluate the influence of different π-conjugation levels in cyclometalating ligands and determine the most efficient ligand for energy conversion in the nanocomposite. The analysis covers seven distinct Ir(III) complexes, each featuring a common bpy ligand but differing diimine ligands. These complexes are linked to GQDs through amide connections. The study comprehensively examines electronic structure, absorption spectra, charge transfer, and chemical reactivity. Our results show that increased ligand π-conjugation causes a redshift in the absorption spectrum due to smaller highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps, ultimately enhancing light harvesting. This effect becomes more pronounced when GQDs are incorporated. For less-conjugated ligands, attaching GQDs enhances metal-to-ligand charge transfer, facilitating electron injection into TiO2. Moreover, higher conjugation and GQD coupling reduce chemical hardness while increasing chemical potential and electrophilicity, thus improving electron acceptance. Furthermore, strategic structural variations modify free energy changes for electron injection and ground-state regeneration. Notable is the inclusion of perylene and pyrene moieties in the ligand, which accelerates injection and extends recombination lifetimes, while GQD incorporation accelerates injection across all ligands. Additionally, photocurrent generation primarily influences energy conversion efficiency. Finally, adding GQDs enhances the first-order hyperpolarizability, further boosting light harvesting. This study demonstrates the potential of tuning ligand π-conjugation and GQD interfaces to optimize optoelectronic properties and charge transfer dynamics, thereby enhancing solar energy conversion in GQD/Ir(III) complex systems.

7.
Mol Cell ; 82(24): 4712-4726.e7, 2022 12 15.
Article in English | MEDLINE | ID: mdl-36423631

ABSTRACT

Programmed cell death and caspase proteins play a pivotal role in host innate immune response combating pathogen infections. Blocking cell death is employed by many bacterial pathogens as a universal virulence strategy. CopC family type III effectors, including CopC from an environmental pathogen Chromobacterium violaceum, utilize calmodulin (CaM) as a co-factor to inactivate caspases by arginine ADPR deacylization. However, the molecular basis of the catalytic and substrate/co-factor binding mechanism is unknown. Here, we determine successive cryo-EM structures of CaM-CopC-caspase-3 ternary complex in pre-reaction, transition, and post-reaction states, which elucidate a multistep enzymatic mechanism of CopC-catalyzed ADPR deacylization. Moreover, we capture a snapshot of the detachment of modified caspase-3 from CopC. These structural insights are validated by mutagenesis analyses of CopC-mediated ADPR deacylization in vitro and animal infection in vivo. Our study offers a structural framework for understanding the molecular basis of arginine ADPR deacylization catalyzed by the CopC family.


Subject(s)
Calmodulin , Caspases , Animals , Calmodulin/genetics , Calmodulin/metabolism , Caspases/metabolism , Caspase 3/metabolism , Arginine , Catalysis , Bacterial Proteins/genetics , Bacterial Proteins/metabolism
8.
Sci Rep ; 10(1): 17139, 2020 10 13.
Article in English | MEDLINE | ID: mdl-33051547

ABSTRACT

It is of great significance for the efficient utilization of water resources and the construction of the ecological environment in China to fully understand the evolution process of the spatial-temporal pattern of evapotranspiration (ET). With the use of the v2.0 and v2.1 ET data sets combined with the Global Land Data Assimilation System and Noah model, this paper selects pixels as the basic research object to analyse the spatial-temporal variation in ET in China during the 71 years from 1948 to 2018. We first applied the TFPW-MK test to study the annual ET trend in China throughout the 71-year period, including the ET trend of each month from January to December and the annual total ET trend. Moreover, we examined the spatial variation in these trends. In addition, we calculated the variation coefficient of the time series of each pixel's ET throughout the 71-year period and the variation coefficient of the spatial distribution of ET in each year to analyse the spatial-temporal fluctuations in ET in the study area. Finally, the Hurst index was adopted to evaluate the future ET trend. Based on these analyses, we observed the following novel spatial-temporal characteristics of ET: from 1948 to 2018, (1) the ET in most regions covered by 89.5% of all pixels in China exhibits an increasing trend. (2) The ET trend in China varies greatly with the change in months, and many regions show the most or least obvious increasing trend (or decreasing trend) at different times. (3) The area with an increasing trend is the largest in May and the smallest in December, and more than half of the pixels in all months of a year reveal an increasing trend. (4) In the northeast, west and south regions of China, the monthly fluctuation in the ET trend is relatively large, which indicates that the ET trend in these regions is greatly affected by the month. (5) The fluctuation in ET in China is larger in the north than it is in the south and larger in the west than it is in the east. The most stable fluctuation occurs in East China. (6) The ET trend of almost all the pixels in the study area remains consistent from 1948 to 2018, and there are large areas with a notable continuity. This results in the spatial variation in ET in the study area increasing.

9.
Mediators Inflamm ; 2020: 2675785, 2020.
Article in English | MEDLINE | ID: mdl-32684832

ABSTRACT

Acupuncture is a key component of Chinese medicine. It describes a series of procedures involving the stimulation of skin through penetration of fine, single-use, sterile needles that result in the release of neurotransmitters. Although its use is on the growing trend, considerable controversy surrounds its value as a therapy. Standard randomized controlled trials that adhere to the accepted criteria should be conducted in the future to ensure the effectiveness of acupuncture. This article summarizes the current evidence regarding the use of acupuncture. It includes a description of the history, mode of operation, treatment of a variety of chronic disorders related to inflammation, and future directions for acupuncture use. Published clinical trials support the view that acupuncture is a possible candidate for the treatment of several chronic inflammation-related disorders.


Subject(s)
Acupuncture Therapy/methods , Chronic Disease/therapy , Inflammation/therapy , Acupuncture Therapy/trends , Female , Humans , Male
10.
Neuropsychologia ; 137: 107301, 2020 02 03.
Article in English | MEDLINE | ID: mdl-31821831

ABSTRACT

Both language experience and processing strategy have been found to affect functional lateralization of the ventral occipitotemporal cortex (vOT). In this study, we adopted a factorial design to investigate the effects of language experience and processing strategy on functional lateralization of different vOT subregions in the processing of familiar (Chinese characters) and unfamiliar characters (Korean Hangul characters) in logographic writings. The processing strategy was manipulated by using part- and whole-based judgement tasks to induce part- and whole-based processing, respectively. The results showed that language experience enhanced neural responses in the anterior and middle vOT subregions, whereas part-based processing enhanced neural activations in the middle and posterior vOT subregions. More importantly, increased neural activations in the left hemisphere induced by language experience and part-based processing resulted in left laterality of the anterior and posterior vOT subregions, respectively, in the processing of logographic characters. These results suggested that functional lateralization of the anterior and posterior vOT subregions were respectively affected by language experience and processing strategy.


Subject(s)
Brain Mapping , Functional Laterality/physiology , Language , Occipital Lobe/physiology , Pattern Recognition, Visual/physiology , Practice, Psychological , Temporal Lobe/physiology , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Occipital Lobe/diagnostic imaging , Reading , Temporal Lobe/diagnostic imaging , Young Adult
11.
Zhongguo Zhen Jiu ; 39(10): 1051-4, 2019 Oct 12.
Article in Chinese | MEDLINE | ID: mdl-31621255

ABSTRACT

OBJECTIVE: To compare the clinical effect of wrist-ankle needle combined with opioid drugs and opioid drugs alone in treating refractory cancer pain. METHODS: Sixty patients were randomly divided into an observation group and a control group, 30 cases in each one. The opioid drugs in accordance with the three-step analgesic principle and other auxiliary drugs were treated in the control group. On the basis of the treatment in the control group, wrist-ankle needle was added in the observation group, and acupoints were selected according to the pain site and the primary focus, the treatment was given once a day for 10 days. The visual analogue scale (VAS) score, the times of pain outbreaks and the incidence of adverse reactions were compared at the 2nd, 4th, 6th, 8th and 10th days of treatment and the 3rd and 7th days after treatment. The therapeutic effect in the two groups were compared after treatment. RESULTS: Compared with the control group, the VAS scores in the observation group were significantly reduced from the 2nd day of wrist-ankle needle treatment, and continued to the 3rd day after the end of the treatment (P<0.05), but there was no statistically significant difference between the two groups on the 7th day after the end of the treatment (P>0.05); compared with the control group, the times of pain outbreaks in the observation group decreased from the 2nd day to the 10th day of treatment (all P<0.05); the incidence of nausea, vomiting and constipation in the observation group was significantly reduced compared with the control group (P<0.05); the total effective rate in the observation group was 86.7% (26/30), which was higher than 76.7% (23/30) in the control group (P<0.05). CONCLUSION: Wrist-ankle needle combined with opioid drugs can increase the efficacy of the refractory cancer pain and reduce the adverse reactions of opioid drugs.


Subject(s)
Acupuncture Analgesia/methods , Analgesics, Opioid/therapeutic use , Cancer Pain , Ankle , Cancer Pain/therapy , Humans , Treatment Outcome , Wrist
12.
Molecules ; 23(7)2018 Jun 27.
Article in English | MEDLINE | ID: mdl-29954113

ABSTRACT

β-1,3-Glucanase is considered as a useful enzymatic tool for β-1,3-glucan degradation to produce (1→3)-linked β-glucan oligosaccharides with pharmacological activity properties. To validly isolate β-1,3-glucanase-producing microorganisms, the soil of Wolfiporia extensa, considered an environment rich in β-1,3-glucan-degrading microorganisms, was subjected to high throughput sequencing. The results demonstrated that the genera Streptomyces (1.90%) and Arthrobacter (0.78%) belonging to the order Actinomycetales (8.64%) in the phylum Actinobacteria (18.64%) were observed in soil for P. cocos cultivation (FTL1). Actinomycetes were considered as the candidates for isolation of glucan-degrading microorganisms. Out of 58 isolates, only 11 exhibited β-1,3-glucan-degrading activity. The isolate SYBCQL belonging to the genus Kitasatospora with β-1,3-glucan-degrading activity was found and reported for the first time and the isolate SYBC17 displayed the highest yield (1.02 U/mg) among the isolates. To check the β-1,3-glucanase contribution to β-1,3-glucan-degrading activity, two genes, 17-W and 17-Q, encoding β-1,3-glucanase in SYBC17 and one gene QLK1 in SYBCQL were cloned and expressed for verification at the molecular level. Our findings collectively showed that the isolates able to secrete β-1,3-glucanase could be obtained with the assistance of high-throughput sequencing and genes expression analysis. These methods provided technical support for isolating β-1,3-glucanase-producing microorganisms.


Subject(s)
Glycoside Hydrolases/metabolism , Actinobacteria/metabolism , Arthrobacter/metabolism , Molecular Biology , Soil Microbiology , Streptomyces/metabolism , Wolfiporia
13.
Yao Xue Xue Bao ; 42(4): 440-4, 2007 Apr.
Article in Chinese | MEDLINE | ID: mdl-17633216

ABSTRACT

Methoxypolyethylene glycol-poly lactic acid (PELA) was synthesized by ring-opening copolymerization of lactide in the presence of mPEG and its structure was characterized by 1H NMR. The novel hypomicrons were prepared by solution-casting method using PELA block copolymer as a matrix and 7-ethyl-10-hydroxycamptothecin (SN-38) as an antitumor agent. The morphology, size and size distribution, drug loading, entrapment efficiency, and release characteristics in vitro of the SN-38 loaded hypomicrons were studied. The results showed that the obtained hypomicrons showed spherical shape with the core-shell structure, the sizes are in the range of 157-238 nm, and the drug loading content varied from 1.35%-3.58% depending on the copolymer composition and the SN-38 fed amount. The in vitro release behavior in phosphate-buffered saline, pH 7.4, exhibited a sustaining release manner and was affected by the copolymer composition. The drug-loaded amount and entrapment efficiency decreased with increasing the molecular weight of the copolymer. With the increasing of the SN-38 fed amount, the drug-loaded amount and the size of hypomicrons increased, the entrapment efficiency decreased. The SN-38 hypomicrons increased the solubility of SN-38 in water and were valuable for the development of the novel dosage form of SN-38.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Camptothecin/analogs & derivatives , Camptothecin/administration & dosage , Drug Carriers , Irinotecan , Lactic Acid/chemistry , Microspheres , Particle Size , Polyesters , Polyethylene Glycols/chemistry , Polymers/chemistry , Solubility , Technology, Pharmaceutical
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