Evaluating the Gilbert-Varshamov Bound for Constrained Systems.

We revisit the well-known Gilbert-Varshamov (GV) bound for constrained systems. In 1991, Kolesnik and Krachkovsky showed that the GV bound can be determined via the solution of an optimization problem. Later, in 1992, Marcus and Roth modified the optimization problem and improved the GV bound in many instances. In this work, we provide explicit numerical procedures to solve these two optimization problems and, hence, compute the bounds. We then show that the procedures can be further simplified when we plot the respective curves. In the case where the graph presentation comprises a single state, we provide explicit formulas for both bounds.

Characterization of Altered Oropharyngeal Microbiota in Hospitalized Patients With Mild SARS-CoV-2 Infection.

Coronavirus disease 2019 (COVID-19) remains a serious emerging global health problem, and little is known about the role of oropharynx commensal microbes in infection susceptibility and severity. Here, we present the oropharyngeal microbiota characteristics identified by full-length 16S rRNA gene sequencing through the NANOPORE platform of oropharynx swab specimens from 10 mild COVID-19 patients and 10 healthy controls. Our results revealed a distinct oropharyngeal microbiota composition in mild COVID-19 patients, characterized by enrichment of opportunistic pathogens such as Peptostreptococcus anaerobius and Pseudomonas stutzeri and depletion of Sphingomonas yabuuchiae, Agrobacterium sullae, and Pseudomonas veronii. Based on the relative abundance of the oropharyngeal microbiota at the species level, we built a microbial classifier to distinguish COVID-19 patients from healthy controls, in which P. veronii, Pseudomonas fragi, and S. yabuuchiae were identified as the most prominent signatures for their depletion in the COVID-19 group. Several members of the genus Campylobacter, especially Campylobacter fetus and Campylobacter rectus, which were highly enriched in COVID-19 patients with higher severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load and showed a significant correlation with disease status and several routine clinical blood indicators, indicate that several bacteria may transform into opportunistic pathogen in COVID-19 patients when facing the challenges of viral infection. We also found the diver taxa Streptococcus anginosus and Streptococcus alactolyticus in the network of disease patients, suggesting that these oropharynx microbiota alterations may impact COVID-19 severity by influencing the microbial association patterns. In conclusion, the low sample size of SARS-CoV-2 infection patients (n = 10) here makes these results tentative; however, we have provided the overall characterization that oropharyngeal microbiota alterations and microbial correlation patterns were associated with COVID-19 severity in Anhui Province.

Controlled Growth of Large-Sized and Phase-Selectivity 2D GaTe Crystals.

GaTe has recently attracted significant interest due to its direct bandgap and unique phase structure, which makes it a good candidate for optoelectronics. However, the controllable growth of large-sized monolayer and few-layer GaTe with tunable phase structures remains a great challenge. Here the controlled growth of large-sized GaTe with high quality, chemical uniformity, and good reproducibility is achieved through liquid-metal-assisted chemical vapor deposition method. By using liquid Ga, the rapid growth of 2D GaTe flakes with high phase-selectivity can be obtained due to its reduced reaction temperature. In addition, the method is used to synthesize many Ga-based 2D materials and their alloys, showing good universality. Raman spectra suggest that the as-grown GaTe own a relatively weak van der Waals interaction, where monoclinic GaTe displays highly-anisotropic optical properties. Furthermore, a p-n junction photodetector is fabricated using GaTe as a p-type semiconductor and 2D MoSe2 as a typical n-type semiconductor. The GaTe/MoSe2 heterostructure photodetector exhibits large photoresponsivity of 671.52 A W-1 and high photo-detectivity of 1.48 × 1010 Jones under illumination, owing to the enhanced light absorption and good quality of as-grown GaTe. These results indicate that 2D GaTe is a promising candidate for electronic and photoelectronic devices.

Clinical Analysis of Patients with MGUS, Primary Light Chain Amyloidosis, Multiple Myeloma or Multiple Myeloma with Concurrent Amyloidosis / 中国实验血液学杂志

OBJECTIVE@#To summarize and compare the clinical baseline characteristics of patients with monoclonal gammopathy of undetermined significance (MGUS), primary light chain amyloidosis (pAL), multiple myeloma (MM), or MM with concurrent amyloidosis, especially the differences in cytogenetic abnormalities.@*METHODS@#The clinical data of 15 cases of MGUS, 34 cases of pAL, 842 cases of MM and 23 cases of MM with concurrent amyloidosis were analyzed and compared retrospectively.@*RESULTS@#Cytogenetic statistics showed that the incidence of t (11; 14) in the four groups (MGUS vs pAL vs MM vs MM with concurrent amyloidosis) was 0%, 33.3%, 16.4%, and 15.8%, respectively (P=0.037); that of 13q deletion was 20.0%, 14.7%, 45.8% and 56.5%, respectively (P<0.001); gain of 1q21 was 50.0%, 12.5%, 47.4% and 40.9%, respectively (P=0.001). Proportion of pAL patients with 0, 1 and≥2 cytogenetic abnormalities (including 13q deletion, 17p deletion, 1q21 amplification and IgH translocation) accounted for 41.9%, 41.9% and 16.1%, respectively; while the proportion of the same category in MM was 17.6%, 27.3%, and 55.2% respectively; this ratio of MM with concurrent amyloidosis was more similar to MM. Subgroup analysis showed that genetic abnormalities (including 13q deletion, 17p deletion and 1q21 amplification) were comparable within t (11; 14) negative and positive groups. Compared with positive cases, t(11; 14) negative patients with MM or MGUS were more likely to have 13q deletions and multiple genetic abnormalities.@*CONCLUSION@#Clinical characteristics of pAL, especially cytogenetic abnormalities, are significantly different from MM with concurrent amyloidosis. It suggests that although the onset characteristics are similar, actually the two diseases belong to different disease subtypes which should be carefully predicted and identified.

Specific ablation of CD4+ T-cells promotes heart regeneration in juvenile mice.

Unlike adult cardiomyocytes, neonatal cardiomyocytes can readily proliferate that contributes to a transient regenerative potential after myocardial injury in mice. We have recently reported that CD4+ regulatory T-cells promote this process; however, the role of other CD4+ T-cell subsets as well as CD8+ T-cells in postnatal heart regeneration has been less studied. Methods: by comparing the regenerating postnatal day (P) 3 and the non-regenerating P8 heart after injury, we revealed the heterogeneity of CD4+ and CD8+ T-cells in the myocardium through single cell analysis. We also specifically ablated CD4+ and CD8+ T-cells using the lytic anti-CD4 and -CD8 monoclonal antibodies, respectively, in juvenile mice at P8 after myocardial injury. Results: we observe significantly more CD4+FOXP3- conventional T-cells in the P8 heart when compared to that of the P3 heart within a week after injury. Surprisingly, such a difference is not seen in CD8+ T-cells that appear to have no function as their depletion does not reactivate heart regeneration. On the other hand, specific ablation of CD4+ T-cells contributes to mitigated cardiac fibrosis and increased cardiomyocyte proliferation after injury in juvenile mice. Single-cell transcriptomic profiling reveals a pro-fibrotic CD4+ T-cell subset in the P8 but not P3 heart. Moreover, there are likely more Th1 and Th17 cells in the P8 than P3 heart. We further demonstrate that cytokines of Th1 and Th17 cells can directly reduce the proliferation and increase the apoptosis of neonatal cardiomyocytes. Moreover, ablation of CD4+ T-cells can directly or indirectly facilitate the polarization of macrophages away from the pro-fibrotic M2-like signature in the juvenile heart. Nevertheless, ablation of CD4+ T-cells alone does not offer the same protection in the adult heart after myocardial infarction, suggesting a developmental change of immune cells including CD4+ T-cells in the regulation of age-related mammalian heart repair. Conclusions: our results demonstrate that ablation of CD4+ but not CD8+ T-cells promotes heart regeneration in juvenile mice; and CD4+ T-cells play a distinct role in the regulation of heart regeneration and repair during development.

Synthesis, Structure, Photoluminescence, Energy Transfer Mechanism and Band Gap of a Terbium-Mercury Complex with a 3-D Framework.

A novel terbium-mercury compound [Tb(IA)3(H2O)2(Hg2Cl4)]n·nHgCl2·nH2O (1, HIA = isonicotinic acid) was prepared via a hydrothermal reaction and structurally characterized through single-crystal X-ray diffraction technique. This compound is characterized by a three-dimensional (3-D) framework. Photoluminescence experiments with solid-state samples uncovered that this compound can show yellow light emission with the emission peaks at 490, 545, 586 and 621 nm, respectively. These photoluminescence emission peaks are originated from the characteristic emission of the 4f electrons intrashell transition of the 5D4 → 7FJ(J = 6, 5, 4, 3) of the Tb3+ ions. An energy transfer mechanism is expatiated by applying the energy level figure of the terbiumions and isonicotinic acid. This compound possesses a remarkable CIE chromaticity coordinates (0.3525, 0.4032). A wide optical band gap of 2.51 eV of the title compound is determined by using the solid-state UV/Vis diffuse reflectance spectroscopy.

Effective treatment of narcolepsy-like symptoms with high-frequency repetitive transcranial magnetic stimulation: A case report.

RATIONALE: Narcolepsy is a rare sleep disorder with disrupted sleep-architecture. Clinical management of narcolepsy lies dominantly on symptom-driven pharmacotherapy. The treatment role of repetitive transcranial magnetic stimulation (rTMS) for narcolepsy remains unexplored. PATIENT CONCERNS: In this paper, we present a case of a 14-year-old young girl with excessive daytime sleepiness (EDS), cataplexy and hypnagogic hallucinations. DIAGNOSES: After excluding other possible medical conditions, this patient was primarily diagnosed with narcolepsy. INTERVENTIONS: The patient received 25 sessions of high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC). OUTCOMES: The symptoms of EDS and cataplexy significantly improved after rTMS treatment. Meanwhile, her score in the Epworth sleep scale (ESS) also remarkably decreased. LESSONS: This case indicates that rTMS may be selected as a safe and effective alternative strategy for treating narcolepsy-like symptoms. Well-designed researches are warranted in future investigations on this topic.

Studies on the function and catalytic mechanism of O-methyltransferases SviOMT02, SviOMT03 and SviOMT06 from Streptomyces virginiae IBL14.

To identify the fuctions of the nine putative O-methyltransferase genes in Streptomyces virginiae IBL14, the evolutionary and functional relationship of these genes in its 8.0 Mb linear chromosome was set up via sequence comparison with those of other Streptomyces species. Further, the functions and catalytic mechanism of the three genes sviOMT02, sviOMT03 and sviOMT06 from this strain were studied through experimental and computational approaches. As a result, the nine putative O-methyltransferases belong to methyltransf_2 superfamily, amdomet-MTases superfamily, and leucine carboxyl methyltransferase superfamily, and are phylogenetically close to those of Streptomyces sp. C. The products of genes sviOMT03 and sviOMT06 could catalyze O-methylation of caffeic acid to form ferulic acid. Computational analysis indicated that the O-methylation mechanism of SviOMT03 and SviOMT06 proceeds from a direct transfer of the SAM-methyl group to caffeic acid with inversion of symmetry aided by a divalent metal ion in a SN2-like mechanism. Particularly, the conservative polar amino acid residues in SviOMT03 and SviOMT06, including Lys143 that reacts with caffeic acid, Ser74, Asp140 and Tyr149 that react with S-adenosyl methionine, and His142 (SviOMT03) or His171 (SviOMT06) that transfers the 3-hydroxyl proton of substrate caffeic acid, probably be essential in their O-methylation.

[Effects of elevated ozone concentration on CO2 emission from soil-winter wheat system].

To investigate the impact of elevated ozone (O3) on CO2 emission from soil-winter wheat system, outdoor experiments with simulating elevated O3 concentration were conducted, and static dark chamber-gas chromatograph method was used to measure CO2 emission fluxes. Results indicated that the elevated O3 did not change the seasonal pattern of CO2 emissions from soil-winter wheat system, but significantly decreased CO2 emission fluxes during turning-green stage and elongation-pregnant stage. From heading to maturity, CO2 emission fluxes were not found to be significant difference under 100 nL x L(-1) O3 treatment compared with the control, while 150 nL x L(-1) O3 treatment significantly declined CO2 emission fluxes. Significant relationships were found between respiration rate and air temperature under the control, 100 nL x L(-1) and 150 nL x L(-1) O3 treatment, and the fitting equation determined coefficients R2 were 0.139, 0.513 and 0.211, respectively. In addition, the Q10 (temperature sensitivity coefficients) for soil-winter wheat system's respiration were 1.13, 1.58 and 1.21, respectively. The results of this study suggested that elevated O3 could reduce CO2 emissions from agroecosystem.

[Effects of simulated nitrogen deposition on soil respiration in northern subtropical deciduous broad-leaved forest].

To investigate the effects of elevated nitrogen deposition on forest soil respiration, a simulated nitrogen deposition field experiment was conducted in northern subtropical deciduous broad-leave forest from April 2008 to April 2009. Nitrogen treatments included the control (no N addition, CK), low-N [50 kg x (hm2 x a)(-1), T(L)], medium-N [100 kg x (hm2 x a)(-1), T(M)], and high-N [150 kg x (hm2 x a)(-1), T(H)]. The respiration rates were measured by a static chamber-gas chromatograph method. Results showed that nitrogen deposition did not change the seasonal and daily variation patterns of soil respiration. Compared to the control, T(L), T(M) and T(H) treatments reduced soil annual average respiration rates by 8.51%, 9.74% and 11.24%, respectively. Meanwhile, T(L), T(M) and T(H) treatments decreased daily average soil respiration rates by 4.42%, 11.09% and 12.17%, respectively. Significant relationship was found between soil respiration rate and soil temperature. The Q10 (temperature sensitivity coefficients) for soil respiration of CK, T(L), T(M), and T(H) treatments were 2.53, 3.22, 2.64 and 2.92, respectively. Our findings suggested that nitrogen deposition reduced soil respiration, and increased soil respiration temperature sensitivity in northern subtropical deciduous broad-leave forest.

[Influence of enhanced UV-B radiation and straw application on soil respiration in soybean field].

Field experiment was carried out in 2008 in order to investigate the effects of enhanced UV-B radiation and straw application on soil respiration in soybean field. LI-8100 automated soil CO2 flux system was used to measure soil respiration under 20% enhanced UV-B radiation, straw application, 20% enhanced UV-B radiation + straw application and control. Environmental factors such as air temperature, soil temperature and moisture were also measured. Results indicated that supplemental UV-B radiation reduced soil respiration rate by 30.31%, straw application increased soil respiration rate by 14.51%, while enhanced UV-B radiation + straw application combined treatment had no significant effect on soil respiration. Enhanced UV-B radiation enhanced the carbon conversion rate of straw. Significant relationship were found between soil respiration rate and soil temperature under the control, enhanced UV-B, straw application, and enhanced UV-B + straw application, the fitting equation determined coefficients R2 were 0.434, 0.563, 0.451 and 0.513. The Q10 (temperature sensitivity coefficients) for soil respiration were 1.55, 1.91, 1.80 and 1.71, respectively. It was reflected that enhanced UV-B radiation, straw application and enhanced UV-B radiation + straw returning increased the Q10 for soil respiration.

[Temperature sensitivity of wheat plant respiration and soil respiration influenced by increased UV-B radiation from elongation to flowering periods].

Field experiment was carried out in the spring of 2008 in order to investigate the effects of increased UV-B radiation on the temperature sensitivity of wheat plant respiration and soil respiration from elongation to flowering periods. Static chamber-gas chromatography method was used to measure ecosystem respiration and soil respiration under 20% UV-B radiation increase and control. Environmental factors such as temperature and moisture were also measured. Results indicated that supplemental UV-B radiation inhibited the ecosystem respiration and soil respiration from wheat elongation to flowering periods, and the inhibition effect was more obvious for soil respiration than for ecosystem respiration. Ecosystem respiration rates, on daily average, were 9%, 9%, 3%, 16% and 30% higher for control than for UV-B treatment forthe five measurement days, while soil respiration rates were 99%, 93%, 106%, 38% and 10% higher for control than for UV-B treatment. The Q10s (temperature sensitivity coefficients) for plant respiration under control and UV-B treatments were 1.79 and 1.59, respectively, while the Q10s for soil respiration were 1.38 and 1.76, respectively. The Q10s for ecosystem respiration were 1.65 and 1.63 under CK and UV-B treatments, respectively. Supplemental UV-B radiation caused a lower Q10 for plant respiration and a higher Q10 for soil respiration, although no significant effect of supplemental UV-B radiation on the Q10 for ecosystem respiration was found.

[Influence of enhanced UV-B radiation on chlorophyll fluorescence characteristics of soybean].

To investigate the influence of enhanced UV-B radiation on chlorophyll fluorescence characteristics of soybean, pulse amplitude modulation fluorometer was employed to measure the fluorescence parameters and rapid light curves during different growth stages under the condition of simulating 20% enhancement of UV-B. Results showed that enhanced UV-B radiation reduced the chlorophyll contents by 5.03%, 7.70% and 10.38% in seedling, branching-flowering and pod-setting periods, respectively. In branching-flowering period, the value of Fv/Fm decreased by 6.13%. In seedling and branching-flowering periods, effective quantum yield(Y) diminished significantly during PAR >366 micromol x (m2 x s)(-1), the maximal potential relative electron transport rate (Pm) diminished by 28.92% and 15.49%, respectively. But Y and Pm had no significant difference in 3-leave and pod setting periods. Semi-light saturation points (l(k)) were diminished by 21.18% and 23.17% in 3-leave and seedling periods. Initial slope (a) was decreased by 21.05% in branching-flowering period. Enhanced UV-B radiation also significantly reduced non-photochemical quenching (NPQ) during PAR >366 micromol x (m2 x s)(-1) in seedling period and photochemical quenching (qP) during PAR >366 micromol x (m2 x s)(-1) in branching-flowering period. The results of this study suggested that enhanced UV-B radiation inhibited electron transport activity of PS II, injured light-harvesting systems and dissipative protection mechanisms, damaged photosynthesis system, thus diminished photosynthetic efficiency of soybean.

Investigation of stressful life events in patients with systemic sclerosis.

OBJECTIVE: To assess the occurrence of stressful life events in the year before the initiation of systemic sclerosis. METHODS: A consecutive series of 40 patients with systemic sclerosis (mean age (56.3+/-11.9) years, mean disease duration (4.3+/-3.1) years; 32 females and 8 males), including 28 with diffuse cutaneous scleroderma and 12 with limited cutaneous scleroderma, were evaluated. A control group of 40 healthy subjects free of systemic sclerosis also was included. Socioeconomic status was investigated and Paykel's interview for recent life events (a semi-structured research interview covering 64 life events) was conducted. RESULTS: Patients with systemic sclerosis showed higher percentages of lower education (72.5%) and working class (82.5%), and reported more stressful life events (P<0.05), such as exits (P<0.05), undesirable events (P<0.01), and uncontrolled events (P<0.001), when compared with the control. More events that had an objective negative impact (P<0.001) were also reported in systemic sclerosis patients than in the control. These results are in accordance with a multifactorial model of pathogenesis in systemic sclerosis. CONCLUSION: We reported a strong relationship between stressful life events and the initiation of systemic sclerosis. Our findings are consistent with current understanding of the extensive links of behavioral responses to stress with neurophysiological and biochemical processes.

[Hemocompatibility of bovine pericardium with additional sodium bisulfite treatment].

OBJECTIVE: To evaluate the hemocompatibility of glutaraldehyde (GA)-tanned bovine pericardium additionally treated by sodium bisulfite (SOB) solution. METHODS: The hemocompatibility of GA-tanned bovine pericardium treated by SOB solution is evaluated by using dynamic clotting time test, blood platelet adhension test, D-dimeride determination, and complement activation test. The GA-tanned bovine pericardium was used as control. RESULTS: The curve of absorbance-clotting time of two kinds of bovine pericardium was similar in dynamic clotting time test. There was no significant difference between SOB-treated and control groups in blood platelet adhension test. The D-dimeride contents of all bioprostheses were at normal level, and the D-dimeride content of GA-tanned bovine pericardium treated by SOB solution was significantly lower than that of control group (P < 0.05). In complement activation test, the level of complement C3a in SOB-treated group was significantly lower than that in control group (P < 0.05). CONCLUSION: GA-tanned bovine pericardium treated by SOB solution meets the demands of cardiac interstitial implanted materials in hemocompatibility.

4,4'-Bipyridinium tetrabromocadmate(II) with strong fluorescence.

The title compound, (C10H10N2)[CdBr4], was synthesized via a hydrothermal reaction. Its structure features discrete 4,4'-bipyridinium cations and tetrahedral [CdBr4]2- anions linked into ion pairs by single N-H...Br hydrogen bonds. Photoluminescent investigation reveals that the title compound displays a strong emission in the blue region, which may originate from pi --> pi* charge-transfer interactions of the 4,4'-bipyridinium cations.