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1.
RSC Adv ; 14(35): 25811-25819, 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-39156750

ABSTRACT

Photocatalytic degradation technology, as one of the most important advanced oxidation technologies for environmental remediation, has attracted great attention in recent years, but designing photocatalysts with excellent photocatalytic activity and good reusability remains a challenge. Herein, three CoS/CoO microspheres (CoS/CoO-M-1 (1), CoS/CoO-M-2 (2), and CoS/CoO-M-3 (3)) were prepared via a hydrothermal method using cobalt chloride hexahydrate, thiourea, deionized water and polyethylene glycol (PEG) with different polymerization degrees as raw materials, which have a uniform size distribution in the range of 5-24 µm and specific surface areas of 6.1924 m2 g-1 (1), 6.2870 m2 g-1 (2) and 6.6663 m2 g-1 (3). It is worth noting that all the three CoS/CoO microspheres showed a wide optical absorption range from the ultraviolet to the near-infrared (NIR) region and a high photocatalytic activity for degrading methyl blue under visible light (500 W metal halide lamp) irradiation. In order to improve the portability and recyclability of 3, a mixed matrix membrane (MMM) of 3 (3-MMM) was manufactured by coating a mixture dispersion of 3 and polyvinylidene fluoride (PVDF) on a glass substrate, which not only displayed excellent photocatalytic degradation performance, but also showed good portability and reusability (cycles > 12 times). Furthermore, adsorption and photocatalytic kinetics and possible mechanisms were studied.

2.
Front Med (Lausanne) ; 11: 1328750, 2024.
Article in English | MEDLINE | ID: mdl-38348339

ABSTRACT

Introduction: While new targeted therapies have advanced psoriasis treatment, real-world data on comparative effectiveness is lacking. This study analyzed treatment regimens and response in an observational cohort, examining potential disparities between clinical trials and routine practice. Methods: Data from the Psoriasis Standardized Diagnosis and Treatment Center registry were analyzed. Patients with ≥1 follow-up were included. Treatment response was assessed using PASI 50/90 criteria. Factors associated with response were analyzed. Results: 407 patients were included (46 first-time diagnosed, 361 previously diagnosed). A higher proportion of first-time diagnosed patients achieved treatment response than previously diagnosed (76.1% vs. 62.6%). Multivariable analysis identified factors associated with reduced response in previously treated patients. Conclusion: This real-world study found lower treatment response rates compared to clinical trials, especially in previously treated patients. Disparities highlight remaining unmet needs for psoriasis management. Combination and rotational strategies may improve outcomes in patients unresponsive to available therapies. Ongoing research on novel targets and pathways is warranted to address treatment gaps.

3.
J Eur Acad Dermatol Venereol ; 38(3): 549-556, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38100231

ABSTRACT

BACKGROUND: Data on nail psoriasis (PsO) in China are scarce. OBJECTIVES: To provide nail PsO-related data regarding epidemiologic characteristics, manifestations, fungal infections, arthritic complaints and treatments that may facilitate improved patient management globally. METHODS: From August 2021 to August 2022, patients with nail PsO were enrolled in a prospective multicentre observational study at 25 hospitals in China. We collected and analysed data concerning nail PsO demography, clinical signs, fungal detection, arthritic symptoms and treatment. RESULTS: A total of 817 patients with nail PsO were involved, with a mean body mass index of 24.13 ± 2.93. In addition, 71.41% of the patients were male. The Nail PsO Severity Index score was weakly positively correlated with body surface area. The percentage of nail involvement was 95.29% for fingernails and 57.18% for toenails, with pitting (67.11%) and subungual hyperkeratosis (60.40%) being the most prevalent manifestations, respectively. Toenails showed a significantly higher frequency of nailfold scales, subungual hyperkeratosis and nail plate crumbling and a lower frequency of splinter haemorrhages, pitting and erythema of the lunula. A total of 13.26% of the PsO patients had onychomycosis, and 77.08% were observed in the toenails. Articular symptoms were reported by 12.17% of the patients, with the peripheral type being predominant. Significant associations between articular symptoms and nailfold swelling, subungual hyperkeratosis, nailfold scales, onycholysis and longitudinal ridges were found. Only 2.30% (20 out of 871) of patients with nail PsO received treatment. The most frequently employed therapy for cutaneous PsO with nail involvement was biologic therapy (n = 366). CONCLUSIONS: PsO showed distinct manifestations in the toenails and fingernails. Additionally, toenail PsO combined with onychomycosis requires special attention. Articular symptoms in psoriatic patients are associated with specific nail changes. It is important to research and advocate for more potent treatments for nail PsO.


Subject(s)
Nail Diseases , Onychomycosis , Psoriasis , Humans , Male , Female , Onychomycosis/diagnosis , Prospective Studies , Nail Diseases/diagnosis , Psoriasis/epidemiology , Psoriasis/therapy , Psoriasis/complications , China/epidemiology
4.
Front Immunol ; 14: 1218475, 2023.
Article in English | MEDLINE | ID: mdl-37771578

ABSTRACT

Background: Relapsing polychondritis (RP) with cardiac involvement may present with acute cardiovascular events, and may be associated with a negative prognosis. Herein, we analyzed the clinical characteristics of RP patients with cardiac involvement. Method: RP patients, hospitalized from December 2005 to December 2021 at Peking Union Medical College Hospital (PUMCH), were screened. Univariate and multivariate logistic regression analyses were used to statistically analyze the clinical characteristics of these patients. Results: The incidence of cardiac involvement in inpatients with RP was 24.1%. Univariate logistic regression analysis revealed age, central nervous system (CNS) involvement, neutrophil-to-lymphocyte ratio (NLR) > 6.41, and disease duration > 4 years as risk factors for cardiac involvement in RP. Conversely, the incidence of tracheobronchial and chest wall involvement was significantly lower in the group with cardiac involvement. Multivariate logistic regression confirmed that age, CNS involvement, NLR > 6.41, and disease duration > 4 years were independent factors for cardiac involvement. Subsequently, we identified five well-defined clinical patterns of RP, based on the involvement of different organs in our patients, and found that the heart-brain model was significantly mutually exclusive with the airway model. Conclusion: Occurrence of cardiac involvement in RP is associated with age, CNS involvement, NLR, and disease duration. It is mutually exclusive with airway-related involvement. Regular echocardiography and electrocardiography are necessary for patients with RP.


Subject(s)
Polychondritis, Relapsing , Humans , Child, Preschool , Polychondritis, Relapsing/diagnosis , Polychondritis, Relapsing/epidemiology , Polychondritis, Relapsing/complications , Prognosis , Respiratory System
5.
Cells ; 10(9)2021 09 08.
Article in English | MEDLINE | ID: mdl-34571998

ABSTRACT

The bacterial microbiota in the skin and intestine of patients with psoriasis were different compared with that of healthy individuals. However, the presence of a distinct blood microbiome in patients with psoriasis is yet to be investigated. In this study, we investigated the differences in bacterial communities in plasma-derived extracellular vesicles (EVs) between patients with moderate to severe psoriasis (PSOs) and healthy controls (HCs). The plasma EVs from the PSO (PASI > 10) (n = 20) and HC (n = 8) groups were obtained via a series of centrifugations, and patterns were examined and confirmed using transmission electron microscopy (TEM) and EV-specific markers. The taxonomic composition of the microbiota was determined by using full-length 16S ribosomal RNA gene sequencing. The PSO group had lower bacterial diversity and richness compared with HC group. Principal coordinate analysis (PCoA)-based clustering was used to assess diversity and validated dysbiosis for both groups. Differences at the level of amplicon sequence variant (ASV) were observed, suggesting alterations in specific ASVs according to health conditions. The HC group had higher levels of the phylum Firmicutes and Fusobacteria than in the PSO group. The order Lactobacillales, family Brucellaceae, genera Streptococcus, and species Kingella oralis and Aquabacterium parvum were highly abundant in the HC group compared with the PSO group. Conversely, the order Bacillales and the genera Staphylococcus and Sphihgomonas, as well as Ralstonia insidiosa, were more abundant in the PSO group. We further predicted the microbiota functional capacities, which revealed significant differences between the PSO and HC groups. In addition to previous studies on microbiome changes in the skin and gut, we demonstrated compositional differences in the microbe-derived EVs in the plasma of PSO patients. Plasma EVs could be an indicator for assessing the composition of the microbiome of PSO patients.


Subject(s)
Extracellular Vesicles/microbiology , Microbiota/genetics , Psoriasis/microbiology , Adult , Aged , Aged, 80 and over , Bacteria/genetics , Dysbiosis/microbiology , Female , Humans , Male , Metagenomics/methods , Middle Aged , Skin/microbiology , Young Adult
6.
J Cosmet Laser Ther ; 21(3): 171-178, 2019.
Article in English | MEDLINE | ID: mdl-30052093

ABSTRACT

BACKGROUND: The 595-nm pulsed dye laser (PDL) has been used to treat vascular anomalies for about 30 years; however, there are insufficient data in Chinese patients concerning therapeutic efficacy, optimized parameters, and procedure techniques. OBJECTIVE: To study the efficacy and relevant factors in PDL therapy for vascular anomalies in Chinese patients. METHOD: We enrolled 431 patients with 8 different vascular anomalies and no previous treatment in this retrospective study. A detailed classification of vascular anomalies and various parameters and techniques of PDL were studied. The clinical outcomes were analysed using the Investigator Global Assessment. RESULTS: Improvements were significantly correlated with infantile haemangioma (IH) subtypes (p < 0.05). A significant correlation between efficacy and lesion colour, anatomical sites, and hypertrophic-type port-wine stain (PWS) was found (p < 0.05). There was no significant correlation between efficacy and age or sex (p > 0.05). CONCLUSION: PDL is an effective and safe therapeutic modality for managing vascular anomalies in Chinese patients. We determined that differentiating and identifying IH subtypes prior to treatment could be a useful parameter for predicting therapeutic results.  Lesion colour, sites, and hypertrophic changes in PWS are relevant therapeutic factors. PDL parameters and techniques differ according to the various vascular anomalies to achieve optimal results.


Subject(s)
Hemangioma, Capillary/radiotherapy , Lasers, Dye/therapeutic use , Low-Level Light Therapy/adverse effects , Low-Level Light Therapy/methods , Port-Wine Stain/radiotherapy , Skin Neoplasms/radiotherapy , Telangiectasis/radiotherapy , Adolescent , Adult , Chi-Square Distribution , Child , Child, Preschool , China , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Photography , Retrospective Studies , Treatment Outcome , Young Adult
7.
Br J Pharmacol ; 170(5): 1027-40, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23909597

ABSTRACT

BACKGROUND AND PURPOSE: Mas oncogene-related gene (Mrg) receptors are exclusively distributed in small-sized neurons in trigeminal and dorsal root ganglia (DRG). We investigated the effects of MrgC receptor activation on inflammatory hyperalgesia and its mechanisms. EXPERIMENTAL APPROACH: A selective MrgC receptor agonist, bovine adrenal medulla peptide 8-22 (BAM8-22) or melanocyte-stimulating hormone (MSH) or the µ-opioid receptor (MOR) antagonist CTAP was administered intrathecally (i.t.) in rats injected with complete Freund's adjuvant (CFA) in one hindpaw. Thermal and mechanical nociceptive responses were assessed. Neurochemicals were measured by immunocytochemistry, Western blot, ELISA and RT-PCR. KEY RESULTS: CFA injection increased mRNA for MrgC receptors in lumbar DRG. BAM8-22 or MSH, given i.t., generated instant short and delayed long-lasting attenuations of CFA-induced thermal hyperalgesia, but not mechanical allodynia. These effects were associated with decreased up-regulation of neuronal NOS (nNOS), CGRP and c-Fos expression in the spinal dorsal horn and/or DRG. However, i.t. administration of CTAP blocked the induction by BAM8-22 of delayed anti-hyperalgesia and inhibition of nNOS and CGRP expression in DRG. BAM8-22 also increased mRNA for MORs and pro-opiomelanocortin, along with ß-endorphin content in the lumbar spinal cord and/or DRG. MrgC receptors and nNOS were co-localized in DRG neurons. CONCLUSIONS AND IMPLICATIONS: Activation of MrgC receptors suppressed up-regulation of pronociceptive mediators and consequently inhibited inflammatory pain, because of the activation of up-regulated MrgC receptors and subsequent endogenous activity at MORs. The uniquely distributed MrgC receptors could be a novel target for relieving inflammatory pain.


Subject(s)
Freund's Adjuvant , Ganglia, Spinal/metabolism , Hyperalgesia/metabolism , Inflammation/metabolism , Pain Threshold , Proto-Oncogene Proteins/metabolism , Receptors, G-Protein-Coupled/metabolism , Analgesics/pharmacology , Animals , Calcitonin Gene-Related Peptide/metabolism , Disease Models, Animal , Ganglia, Spinal/drug effects , Ganglia, Spinal/physiopathology , Gene Expression Regulation , Hyperalgesia/chemically induced , Hyperalgesia/genetics , Hyperalgesia/physiopathology , Hyperalgesia/prevention & control , Inflammation/chemically induced , Inflammation/genetics , Inflammation/physiopathology , Inflammation/prevention & control , Male , Melanocyte-Stimulating Hormones/pharmacology , Narcotic Antagonists/pharmacology , Nitric Oxide Synthase Type I/metabolism , Pain Threshold/drug effects , Peptide Fragments/pharmacology , Proto-Oncogene Mas , Proto-Oncogene Proteins/agonists , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins c-fos/metabolism , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/genetics , Receptors, Opioid, mu/antagonists & inhibitors , Receptors, Opioid, mu/metabolism , Signal Transduction , Somatostatin/pharmacology , Time Factors
8.
Connect Tissue Res ; 54(1): 55-61, 2013.
Article in English | MEDLINE | ID: mdl-23205884

ABSTRACT

OBJECTIVE: To evaluate the effect of polymorphisms of death pathway genes FAS and FASL on the risk of developing lumbar disc herniation (LDH) in a Northern Chinese population. BACKGROUND DATA: The FAS receptor-ligand system plays a key role to regulate apoptosis of cell. There is evidence that the apoptosis-mediated FAS receptor-ligand system is involved in the pathogenesis of disc degeneration. Some research considered single-nucleotide polymorphisms of FAS-1377G/A, FAS-670A/G, FASL-844T/C, and FASL INV2nt-124A/G may increase the risk of developing cancer. We therefore assess these four single-nucleotide polymorphisms as candidate susceptibility for LDH. METHODS: A total of 475 patients with LDH and 533 control subjects were selected. Genotypes were determined by polymerase chain reaction-based restriction fragment length polymorphism and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Associations with the risk of LDH were estimated by logistic regression model. RESULTS: Significant differences were found in genotypic distributions between cases and controls for FASL-844T/C, but not for other three polymorphisms. When compared with CC genotype, subjects with the TT genotype had a higher risk to develop LDH (odds ratio = 3.12; 95% confidence interval: 1.73-5.40). Moreover, an association was found between this genotype of FASL-844TT and more severe grades of disc degeneration. We observed statistically significant interactions between polymorphisms of FASL-844T/C and lumbar load, tobacco smoking, and age. CONCLUSION: Genetic polymorphisms of FASL-844T/C may be associated with an increased risk of developing disc degeneration and LDH.


Subject(s)
Apoptosis/genetics , Asian People/genetics , Fas Ligand Protein/genetics , Intervertebral Disc Displacement/genetics , Polymorphism, Single Nucleotide , fas Receptor/genetics , Adult , Asian People/ethnology , China/ethnology , Female , Humans , Intervertebral Disc Displacement/diagnosis , Intervertebral Disc Displacement/ethnology , Lumbar Vertebrae , Magnetic Resonance Imaging , Male , Middle Aged
9.
Connect Tissue Res ; 52(3): 198-202, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21117896

ABSTRACT

Many studies have demonstrated that apoptosis is involved in the development of disc degeneration. The initiator caspase 9 is activated through the apoptosome-driven intrinsic apoptotic pathway. The present study aimed to assess the potential association between the caspase 9 gene polymorphism and lumbar disc herniation (LDH) susceptibility, as well as severe grades of disc degeneration in the Han population in northern China. Genotyping was performed using the polymerase chain reaction and polymorphism was analyzed by restriction endonuclease cleavage in 387 patients with LDH and 412 control subjects. The allelic frequencies of caspase 9 Ex5+32 A were 0.483 and 0.391 in case patients and control subjects, respectively. Compared to those with the AA genotype, subjects with the GA/GG genotype have a higher risk to develop LDH (odds ratio 1.91; 95% confidence interval 1.29-2.81). Moreover, the GA/GG genotype was found to contribute to the risk of more severe grades of disc degeneration, as observed in magnetic resonance imaging scan. In conclusion, this study suggests that the single nucleotide polymorphism in the caspase 9 Ex5 + 32 G/A may be associated with LDH and disc degeneration in the Han population of northern China.


Subject(s)
Caspase 9/genetics , Ethnicity/genetics , Genetic Predisposition to Disease , Intervertebral Disc Displacement/enzymology , Intervertebral Disc Displacement/genetics , Polymorphism, Single Nucleotide/genetics , Adolescent , Adult , China , Gene Frequency/genetics , Humans , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Young Adult
10.
Sheng Li Ke Xue Jin Zhan ; 42(6): 423-6, 2011 Dec.
Article in Chinese | MEDLINE | ID: mdl-22363980

ABSTRACT

Protein kinase C (PKC) belongs to the AGC (cAMP-dependent protein kinase/PKG/PKC) protein kinase family which plays an important role in the morphine-induced desensitization of R-opioid receptors. This cellular process is believed to contribute to the development and maintenance of morphine tolerance. Therefore, the study of PKC signaling transduction on morphine tolerance has an important clinical significance. The present review summarizes the possible involvement of PKC in opioid tolerance.


Subject(s)
Drug Tolerance , Morphine/pharmacology , Protein Kinase C/physiology , Receptors, Opioid, mu/metabolism , Analgesics, Opioid/pharmacology , Animals , Humans
11.
J Gen Appl Microbiol ; 54(1): 51-60, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18323681

ABSTRACT

Fourteen strains of Lactic Acid Bacteria (LAB) isolated from Qula, a Tibetan traditional yak cheese, were divided into four groups (A-D) according to morphological and biochemical characteristics. On the basis of the 16S rRNA gene sequence analysis, group A and group B strains were placed in the cluster making up the genus Leuconostoc, which together with Leuconostoc mesenteroides and Leuconostoc pseudomesenteroides, formed a distinct cluster. The group C strain was clearly identified as Enterococcus faecium by forming a very well defined cluster with this species. The group D strains were placed in the lactobacilli cluster with Lactobacillus plantarum and Lactobacillus pentosus being the closely related species. On the basis of DNA-DNA hybridization, strains in the groups A, B, C and D were identified as Leuconostoc mesenteroides subsp. dextranicum, Leuconostoc pseudomesenteroides, Enterococcus faecium and Lactobacillus plantarum, respectively. Leuconostoc mesenteroides subsp. dextranicum was the dominate member of the population.


Subject(s)
Cheese/microbiology , Enterococcus faecium , Lactobacillus plantarum , Leuconostoc , Base Composition , Enterococcus faecium/classification , Enterococcus faecium/genetics , Enterococcus faecium/isolation & purification , Fermentation , Lactobacillus plantarum/classification , Lactobacillus plantarum/genetics , Lactobacillus plantarum/isolation & purification , Leuconostoc/classification , Leuconostoc/genetics , Leuconostoc/isolation & purification , Molecular Sequence Data , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Tibet
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(9): 1780-3, 2007 Sep.
Article in Chinese | MEDLINE | ID: mdl-18051528

ABSTRACT

The present article studied the fermentation liquid's absorption spectra, bacteria growth period and elastase' production in elastase fermentation, and compared and analyzed the their relation. The results show that the changes in the absorption spectra were closely related with bacteria growth and elastase' production. The UV spectroscopic technique is helpful for detecting the change of the organic nitrogen base and enzyme. The study offers a new method to detect fermentation process and is basic for detecting fermentation process on line by UV spectroscopic technique.


Subject(s)
Bacillus/enzymology , Bacterial Proteins/chemistry , Culture Media/chemistry , Fermentation , Pancreatic Elastase/chemistry , Spectrophotometry, Ultraviolet/methods , Bacillus/chemistry , Bacterial Proteins/metabolism , Culture Media/metabolism , Pancreatic Elastase/metabolism
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(4): 697-701, 2007 Apr.
Article in Chinese | MEDLINE | ID: mdl-17608178

ABSTRACT

In the present article, the measurement of intact wheat seeds' protein content with near infrared reflentance spectroscopy(NIRS) was studied. The wavelength range of 1 100-2 498 nm was used. The distinguishability of NIRS machine was 2 nm. Firstly the representative wheat samples with different protein contents were selected and the original spectra of wheat were obtained using NIRS machine. Then through scatter correction and maths treatment, spectrum noise were decreased. Finally regression methods used multiple linear regression, principal component regression and modified partial least squares respectively. The result showed that after optimizing all the factors, the best calibration model of equation was chosen using "first derivative" +"Standard Multiplicative Scatter Correction, SMSC"+"Modified Partial Least Squares, MPLS". RSQ, SECV and 1-VR of the obtained calibration model were 0. 94, 0. 42 and 0. 87 respectively. A set of representative individual wheat samples were uesed to check the model, and prediction coefficient of determination was 0.88. Protein content of wheat could be preidicted quickly and scathelessly by using the NIRS measurement. It was feasible to be used in early generation selection in wheat quality breeding process.


Subject(s)
Plant Proteins/analysis , Spectroscopy, Near-Infrared/methods , Triticum/chemistry , Calibration , Seeds/chemistry
14.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(2): 400-3, 2007 Feb.
Article in Chinese | MEDLINE | ID: mdl-17514986

ABSTRACT

The induced variation mechanism of low energy ion beam implantation into a creature has attracted a great attention. DNA was the target of radiation. XPS analysis of thymine sample implanted by low energy N+ was studied. It was found that the relative content of C, N and O changed in the implanted samples. The content of N and O decreased, while that of C increased. Subtle structure of C, N and O was studied. It was found that the peak location of O(1s) shifted. The peak number of N(1s) changed from one to three, while that of C(1s) changed from two to one. The results indicated that the chemical environment and physical structure changed greatly by implantation. N+ implantation could lead to destruction and change of thymine molecular structure.


Subject(s)
Nitrogen/chemistry , Thymine/analysis , Photoelectron Spectroscopy , Thymine/chemistry
15.
Article in English | MEDLINE | ID: mdl-18349504

ABSTRACT

LTR-retrotransposons are genetic elements having the direct long terminal repeats (LTRs). It can move via an RNA intermediate within genomes and is an important fraction of eukaryote genomes. Low-energy N(+) ion beam promoted the transcription of the copia-retransposons in those wheat (cv. 'Zhoumai 16', which were radiated and allowed to grow for 24 h and 48 h from the planting. Relative expression ratio of the copia-retransposons was elevated in different degrees (with a max 40 fold) in wheat plants treated with different doses of N(+) beam, comparing to that in the controls. The molecule markers of the IRAP and REMAP to the DNA isolated from the 14-d leaves of wheat plants treated with the low-energy N(+) beam showed that the transposition of some copia-retransposons was re-activated. The enhanced transcription of the copia-retransposons in wheat could weaken or enhance the expression of their nearby genes. The transposition of the retrotransposon in genome can change the primary structure of the functional DNA fragments of chromosomes, and it can also be visualized as the appearance of a new phenotype of plants. In the mid 1980s, the biological effects of low-energy ion beam were recognized and demonstrated experimentally. Hence, it suggests that the enhanced transcription and the re-activated transposition of the retrotransposons are partially attributed to the biological effect of low-energy ion beam.


Subject(s)
Retroelements/genetics , Retroelements/radiation effects , Transcription, Genetic/radiation effects , Triticum/genetics , Triticum/radiation effects , Genome, Plant/genetics , Genome, Plant/radiation effects , Plant Leaves/genetics , Plant Leaves/radiation effects , Terminal Repeat Sequences/genetics , Terminal Repeat Sequences/radiation effects , Transcription, Genetic/genetics
16.
Phys Rev Lett ; 94(8): 086101, 2005 Mar 04.
Article in English | MEDLINE | ID: mdl-15783905

ABSTRACT

Using first-principles total energy calculations within density functional theory, we investigate the energetics, kinetics, and transport properties of Ti on clean and hydrogen-terminated diamond (100)-2x1 surfaces at increasing Ti coverages. On a clean surface, an isolated Ti adatom prefers to adsorb on top of a C-C dimer row, and also diffuses faster along the dimer row direction. As the Ti coverage increases, the preferred adsorption site converts from an atop site to a site located between the dimer rows. Passivation of the surface at the monohydride coverage not only greatly enhances the Ti mobility, but also weakens the diffusion isotropy. Based on these energetic and kinetic characteristics, we propose a viable approach to fabricate ideal Ti quantum wires on hydrogen-terminated diamond substrates.

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