Enhanced photosynthetic efficiency by nitrogen-doped carbon dots via plastoquinone-involved electron transfer in apple.

Artificially enhancing photosynthesis is critical for improving crop yields and fruit qualities. Nanomaterials have demonstrated great potential to enhance photosynthetic efficiency; however, the mechanisms underlying their effects are poorly understood. This study revealed that the electron transfer pathway participated in nitrogen-doped carbon dots (N-CDs)-induced photosynthetic efficiency enhancement (24.29%), resulting in the improvements of apple fruit qualities (soluble sugar content: 11.43%) in the orchard. We also found that N-CDs alleviated mterf5 mutant-modulated photosystem II (PSII) defects, but not psa3 mutant-modulated photosystem I (PSI) defects, suggesting that the N-CDs-targeting sites were located between PSII and PSI. Measurements of chlorophyll fluorescence parameters suggested that plastoquinone (PQ), the mobile electron carrier in the photosynthesis electron transfer chain (PETC), was the photosynthesis component that N-CDs targeted. In vitro experiments demonstrated that plastoquinone-9 (PQ-9) could accept electrons from light-excited N-CDs to produce the reduced plastoquinone 9 (PQH2-9). These findings suggested that N-CDs, as electron donors, offer a PQ-9-involved complement of PETC to improve photosynthesis and thereby fruit quality. Our study uncovered a mechanism by which nanomaterials enhanced plant photosynthesis and provided some insights that will be useful in the design of efficient nanomaterials for agricultural/horticultural applications.

The AP2/ERF transcription factor MdDREB2A regulates nitrogen utilisation and sucrose transport under drought stress.

Drought stress is one of the main environmental factors limiting plant growth and development. Plants adapt to changing soil moisture by modifying root architecture, inducing stomatal closure, and inhibiting shoot growth. The AP2/ERF transcription factor DREB2A plays a key role in maintaining plant growth in response to drought stress, but the molecular mechanism underlying this process remains to be elucidated. Here, it was found that overexpression of MdDREB2A positively regulated nitrogen utilisation by interacting with DRE cis-elements of the MdNIR1 promoter. Meanwhile, MdDREB2A could also directly bind to the promoter of MdSWEET12, which may enhance root development and nitrogen assimilation, ultimately promoting plant growth. Overall, this regulatory mechanism provides an idea for plants in coordinating with drought tolerance and nitrogen assimilation to maintain optimal plant growth and development under drought stress.

Identification of Phytochrome-Interacting Factor Family Members and Functional Analysis of MdPIF4 in Malus domestica.

Phytochrome-interacting factors (PIFs), members of the basic helix-loop-helix transcription factor family that have been extensively investigated in Arabidopsis thaliana, play essential roles in plant growth and development. However, PIF members have not been systematically investigated in apples, a worldwide perennial woody crop of economic importance. Here, seven PIF genes were identified from the Malus × domestica reference genome. Chromosomal locations, gene structures, and phylogenetic relationships of these members were analyzed. Analysis of cis-acting elements in promoter regions of MdPIF genes indicated that various elements were related to light, abiotic stress, and plant hormone responsiveness. Subsequently, subcellular localization and transcriptional activity analysis revealed that MdPIFs were typical nuclear transcription factors with transcriptional activation ability. Expression analysis demonstrated that MdPIF genes had different gene expression patterns for various abiotic factors. Moreover, overexpressed MdPIF4 reduced the sensitivity of apple calluses to abscisic acid (ABA). Our work lays foundations for further investigation of PIF functions in plant growth and development in apples.

Determination of Protein Interactions among Replication Components of Apple Necrotic Mosaic Virus.

Apple mosaic disease is one of the most widely distributed and destructive diseases in apple cultivation worldwide, especially in China, whose apple yields account for more than 50% of the global total. Apple necrotic mosaic virus (ApNMV) is a newly identified ilarvirus that is closely associated with apple mosaic disease in China; however, basic viral protein interactions that play key roles in virus replication and the viral life cycle have not been determined in ApNMV. Here, we first identify an ApNMV-Lw isolate that belongs to subgroup 3 in the genus Ilarvirus. ApNMV-Lw was used to investigate interactions among viral components. ApNMV 1a and 2apol, encoded by RNA1 and RNA2, respectively, were co-localized in plant cell cytoplasm. ApNMV 1a interacted with itself at both the inter- and intramolecular levels, and its N-terminal portion played a key role in these interactions. 1a also interacted with 2apol, and 1a's C-terminal, together with 2apol's N-terminal, was required for this interaction. Moreover, the first 115 amino acids of 2apol were sufficient for permitting the 1a-2apol interaction. This study provides insight into the protein interactions among viral replication components of ApNMV, facilitating future investigations on its pathogenicity, as well as the development of strategies to control the virus and disease.

Natriuretic peptide family as diagnostic/prognostic biomarker and treatment modality in management of adult and geriatric patients with heart failure: remaining issues and challenges.

B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP), the key members of natriuretic peptide family have been recommended as the gold standard biomarkers for the diagnosis and prognosis of heart failure (HF) according to the current clinical guidelines. However, recent studies have revealed many previously unrecognized features about the natriuretic peptide family, including more accurate utilization of BNP and NT-proBNP in diagnosing HF. The pathophysiological mechanisms behind natriuretic peptide release, breakdown, and clearance are very complex and the diverse nature of circulating natriuretic peptides and fragments makes analytical detection particularly challenging. In addition, a new class of drug therapy, which works via natriuretic peptide family, has also been considered promising for cardiology application. Under this context, our present mini-review aims at providing a critical analysis on these new progresses on BNP and NT-proBNP with a special emphasis on their use in geriatric cardiology settings. We have focused on several remaining issues and challenges regarding the clinical utilization of BNP and NT-proBNP, which include: (1) Different prevalence and diagnostic/prognostic values of BNP isoforms; (2) methodological issues on detection of BNP; (3) glycosylation of proBNP and its effect on biomarker testing; (4) specificity and comparability of BNP/NT-proBNP resulted from different testing platforms; (5) new development of natriuretic peptides as HF treatment modality; (6) BNP paradox in HF; and (7) special considerations of using BNP/NT-proBNP in elderly HF patients. These practical discussions on BNP/NT-proBNP may be instrumental for the healthcare providers in critically interpreting laboratory results and effective management of the HF patients.

Influence of the Ge distribution on the first order magnetic transition of the MnFe(P,Ge) magnetocaloric material.

MnFe(P,Ge) is a promising magnetocaloric material for potential refrigeration applications near room temperature. However, its relatively large hysteresis and large temperature/field range of two-phase [paramagnetic (PM) and ferromagnetic (FM)] coexistence displayed in the cyclic first order magnetic transition (FOMT) cause energy losses and reduce the energy conversion efficiency. In this work, we explore the underlying causes of phase coexistence, hysteresis and structural transformation based on determination of the Ge distribution in MnFeP1-xGex (0.10 < x < 0.50) materials. We find that all the samples crystallize in the Fe2P-type structure [P6[combining macron]2m (No. 189), Z = 3] and Ge displays a strong preference for the 2c site. First principles total energy calculations confirm this site preference of Ge, and Ge entering the 2c site changes the electronic structures and enhances the Fe and Mn 3d exchange splitting across the Fermi level as well as the FM exchange interactions, consequently leading to a linear increase in the transition temperature with increasing Ge content. Scanning electron microscopy and energy-dispersive spectroscopy reveal the inhomogeneous distribution of Ge in grains, which makes the grains with larger Ge content transform from the PM to the FM phase first when cooling and thus causes the phase coexistence. Maximum entropy method electron-densities show that weakening the coplanar Fe-P/Ge(2c) and Mn-P(1b) bonding strengths across the PM to FM phase transition can release some 3d-electrons to enhance the Fe-Mn FM exchange interaction and result in coupling between the magnetic and structural degrees of freedom. This provides first direct evidence for the dominant role of Fe-Mn exchange interaction in the ferromagnetic ordering and may provide a method to observe the exchange interaction. Diminishing the variances in covalent bonding strengths across the FOMT gives rise to an exponential decay in the heat hysteresis when increasing the Ge occupancy at the 2c site. To the best of our knowledge, this is the first time a relationship between the variances in covalent bonding strengths and hysteresis is proposed. This material thus provides an example of a FOMT and hysteresis driven by reversible weakening and strengthening of covalent bonds. Based on these, a strategy of designing better magnetocaloric materials is suggested.

Establishment of reference intervals and transfusion criterion for Sonoclot analysis.

Sonoclot analyzer has been widely used in many countries. But the reference intervals provided by the manufacturer were derived from only 45 participants, and there was no cut-off value for transfusion for Sonoclot analysis. This study aimed to establish reference intervals and transfusion criterion for Sonoclot analysis. Volunteers were recruited from healthy Chinese adults and patients undergoing cardiac surgery. Blood samples were withdrawn from forearm vein and measured for activated clotting time (ACT), clot rate (CR), platelet function (PF), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), and platelet count (PLT). The reference intervals were determined by the nonparametric method. Cut-off values were determined by the receiver operating characteristics curve. A total of 135 healthy volunteers and 281 patients were enrolled. The 95% reference intervals were 96-195 s, 22-51 signal U/min, >1.6 for ACT, CR, PF respectively. In the 281 patients, the results of APTT, FIB, PLT, ACT, CR, and PF ranged from 20.5-300.0 s, 0.28-4.11 g/L, (19.0-387.3)×109/L, 80-514 s, 2.9-74 signal U/min, and 0.1-5.1 respectively. The cut-off values for transfusion were >208, ≤14, and ≤1.3 for ACT, CR, PF respectively. The cut-off values of Sonoclot analysis were within the manufacturer's reference intervals, while they were outside the reference intervals established in this study. The results suggested that the manufacturer's reference intervals were not suitable for Chinese. The reference intervals and cut-off values established in this study will be helpful to Chinese patients.

FADS gene polymorphisms confer the risk of coronary artery disease in a Chinese Han population through the altered desaturase activities: based on high-resolution melting analysis.

OBJECTIVE: We explored the desaturase activities and the correlation of fatty acid desaturases (FADS) gene single nucleotide polymorphisms (SNPs) with plasma fatty acid in coronary artery disease (CAD) patients in a Chinese Han population. METHODS: Plasma fatty acids were measured by gas chromatography in CAD patients (n = 505) and a control group (n = 510). Five SNPs in the FADS gene were genotyped with high-resolution melting (HRM) methods. RESULTS: After adjustment, D6D activity, assessed as arachidonic acid (AA, C20:4n-6)/linoleic acid (LA, C18:2n-6), was higher in CAD patients (p<0.001). D9D activity, which was estimated as the ratio of palmitoleic acid (C16:1)/palmitic acid (C16:0) or oleic acid (C18:1n-9) to stearic acid (C18:0), was also increased (p<0.001). The genotype distributions of rs174537 G>T and rs174460 C>T were different between the two groups. The rs174537 T allele was associated with a lower risk of CAD [OR 0.743, 95% CI (0.624, 0.884), p = 0.001]. Carriers of the rs174460 C allele were associated with a higher risk of CAD [OR 1.357, 95% CI (1.106, 1.665), p = 0.003]. CONCLUSIONS: We firstly report that the rs174460 C allele is associated with a higher risk of CAD, and confirm that the rs174537 T allele is associated with a lower risk of CAD. Our results indicate that FADS gene polymorphisms are likely to influence plasma fatty acid concentrations and desaturase activities.

Evaluation of D-dimer in the diagnosis of suspected aortic dissection.

BACKGROUND: The goal of this study was to evaluate plasma D-dimer as a diagnostic marker for exclusion of suspected aortic dissection (AD). METHODS: Two-hundred and sixty suspected AD patients were enrolled, including acute AD, n=107; chronic AD, n=17; acute myocardial infarction (AMI), n=70; pulmonary embolism (PE), n=18; non-ST elevation myocardial infarction (NSTEMI), n=28; and unstable angina (UA), n=20. All patients had D-dimer testing performed (Roche Diagnostics GmbH) immediately following admission. RESULTS: The D-dimer concentrations in both the acute AD group [median: 3.47; 95% confidence interval (CI): 2.43-4.50 µg/mL] and chronic AD group (median: 1.09; 95% CI: 0.36-3.81 µg/mL) were significantly higher than those in patients in the AMI, NSTEMI and UA groups (p=0.000), but not when compared to the PE group. One (0.8%) patient was identified in the acute AD group who presented with a low D-dimer value (0.04 µg/mL), indicating the existence of intramural hematoma as demonstrated by CT. CONCLUSIONS: D-dimer may be used as a potential marker for suspected AD, with high sensitivity of up to 99.2% (1/124). Regardless of the cut-off threshold selected, the sensitivity of D-dimer was unable to reach 100%. Further examinations, including imaging technology, were necessary to diagnose the suspected AD patients who had negative D-dimer result.

Effect of Jinguo Weikang Capsule on proto-oncogene expression of gastric mucosa in rats with gastric precancerous lesions.

OBJECTIVE: To study the effect of Jinguo Weikang Capsule [see text] on the gene expression of H-ras, epidermal growth factor receptor (EGFR), P53 and C-myc of the gastric mucosa in rats with gastric precancerous lesions, and to investigate the action mechanism of JWC on gastric precancerous lesions. METHODS: A rat model with paratypical proliferation of the gastric epithelium mucosa was established by using 60Co irradiation. Rats were divided into the normal group, model group, high-, medium-, low-dose JWC treatment groups, and the vitacoenzyme control group, and were treated for 30 days. The expression of H-ras, EGFR, P53 and C-myc genes of the gastric mucosa was detected by using immunohistochemical methods. RESULTS: The expression and over-expression rates of H-ras, EGFR, P53 and C-myc gene in the high-and medium-dose JWC treatment groups were significantly lower (P<0.05) as compared with those of the model group. CONCLUSION: JWC can inhibit the expression of the H-ras, EGFR, P53 and C-myc genes expression of the gastric mucosa in rats, which may be one of mechanisms involved in suppressing or reversing gastric carcinogenesis.

[Expression of fibrillin-1 in congenital bicuspid aortic valves].

OBJECTIVE: To detect the expression of fibrillin-1 in congenital bicuspid aortic valves, and to investigate the molecular mechanism of congenital bicuspid aortic valves. METHODS: Specimens of aortic valve were obtained from 12 pediatric patients with congenital bicuspid aortic valve, 11 boys and 1 girl, aged 16.7 (10 - 18), including 5 cases of aortic stenosis (AS), 8 of aortic insufficiency (AI), and 1 of AS and AI, undergoing valve replacement, 8 children who died accidentally without cardiovascular system and collagen system diseases, 6 boys and 2 girls, aged 9.1 (1 - 17), collected in autopsy [normal (tricuspid) aortic valve controls], and 18 pediatric patients of rheumatic valvular heart disease with diseased tricuspid aortic valves who underwent aortic valve replacement, 13 boys and 5 girls, aged 16.5 (12 - 18) (rheumatic valvular heart disease controls). HE staining and light microscopy were conducted. Immunohistochemistry was used to detect the expression of fibrillin-1 in the aortic valves. RESULTS: Microscopy showed that the tissue structure of the congenital bicuspid aortic valves was unclear with hyperplasia of fibrous tissue. The grey degree value of fibrillin-1 of the congenital bicuspid aortic valve group was 170 +/- 10, significantly lower than those of normal aortic valve group and diseased tricuspid aortic valve group (126 +/- 8 and 73 +/- 16 respectively, both P < 0.05). There were not significant difference in the grey degree value of fibrillin-1 among the patients of congenital bicuspid aortic valves with AS, AI, and AS + AI (167 +/- 6, 171 +/- 8, and 168 +/- 6 respectively). CONCLUSION: The expression of fibrillin-1 is significantly reduced in congenital bicuspid aortic valves which may contribute to the morphological changes of the aortic valve leaflets and their resultant functional failure in congenital bicuspid aortic valves.

[The effects of somatostatin on serum interleukin-6 and tumor necrosis factor-alpha in lipopolysaccharide-induced septic shock: experiment with rats].

OBJECTIVE: To explore the effect of somatostatin on serum interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in lipopolysaccharide (LPS)-induced septic shock. METHODS: 24 male Wistar rats were randomly divided into 2 groups: intervention group (injected with LPS of Escherichia coli via femoral vein to induce septic shock) and control group (injected with LPS of Escherichia coli and then injected with somatostatin). The mean arterial pressure (MAP), heart rate, respiration rater, and mortality rate were observed before the injection of LPS, and 30, 90, and 360 min after the injection, and the serum IL-6 and TNF-alpha level were detected before the injection of LPS, 30, 90, and 360 min after the injection, or after the death. RESULTS: The IL-6 levels 30 min, 90 min, and 360 min after the injection of the somatostatin intervention group were 233 +/- 47, 212 +/- 33, and 217 +/- 26 mg/L respectively, all significantly lower then those of the control group (308 +/- 56, 260 +/- 32, and 230 +/- 92 mg/L, all P < 0.05). The TNF-alpha level 30 min, 90 min, and 360 min after the injection of the somatostatin intervention group were 450 +/- 82, 417 +/- 92, and 440 +/- 49 mg/L, all significantly lower than those of the control group (607 +/- 149, 517 +/- 74, and 474 +/- 219 mg/L, all P < 0.05). In addition, compared with the control group, the MAP of the somatostatin intervention group increased after 90 min. Two rats in the control group died 30 to 90 min later and 4 rats died 90 to 360 min later, however, 360 min later all rats in the somatostatin intervention group were alive (P = 0.0054). CONCLUSION: Somatostatin can inhibit the level of serum IL-6 and TNF-alpha in septic shock induced by LPS and improve the survival rate.

[Relativity between occupational stress and psychosocial factors in nurses].

OBJECTIVE: To explore the effect of coping strategies, social support and personality factors, such as locus of control and type A behavior on occupational stress in nurses. METHODS: Descriptive correlation research method was used in this investigation. One thousand nine hundred and one nurses were included by using instruments of Occupational Stress Instrument, and these nurses were divided into four groups according to the scores of occupational stress. RESULTS: There were significant differences in general health status, coping strategies, social support, type A behavior and locus of control in the 4 groups (P < 0.05). The level of individual occupational stress increased with the fall of the scores of coping strategies, social support and with the elevation of type A behavior, locus of control and general health. Occupational stress had negative relation with coping strategies, social support, and positive relation with personalities and general bad health. CONCLUSION: The level of occupational stress is affected by coping strategies, social support, type A behavior and locus of control.