Diaheliotropic leaf movement enhances leaf photosynthetic capacity and photosynthetic light and nitrogen use efficiency via optimising nitrogen partitioning among photosynthetic components in cotton (Gossypium hirsutum L.)

Phototropic leaf movement of plants is an effective mechanism for adapting to light conditions. Light is the major driver of plant photosynthesis. Leaf N is also an important limiting factor on leaf photosynthetic potential. Cotton (Gossypium hirsutum L.) exhibits diaheliotropic leaf movement. Here, we compared the long-term photosynthetic acclimation of fixed leaves (restrained) and free leaves (allowed free movement) in cotton. The fixed leaves and free leaves were used for determination of PAR, leaf chlorophyll concentration, leaf N content and leaf gas exchange. The measurements were conducted under clear sky conditions at 0, 7, 15 and 30 days after treatment (DAT). The results showed that leaf N allocation and partitioning among different components of the photosynthetic apparatus were significantly affected by diaheliotropic leaf movement. Diaheliotropic leaf movement significantly increased light interception per unit leaf area, which in turn affected leaf mass per area (LMA), leaf N content (N_A ) and leaf N allocation to photosynthesis (N_P ). In addition, cotton leaves optimised leaf N allocation to the photosynthetic apparatus by adjusting leaf mass per area and N_A in response to optimal light interception. In the presence of diaheliotropic leaf movement, cotton leaves optimised their structural tissue and photosynthetic characteristics, such as LMA, N_A and leaf N allocation to photosynthesis, so that leaf photosynthetic capacity was maximised to improve the photosynthetic use efficiency of light and N under high light conditions.

LAIR-1 shedding from human fibroblast-like synoviocytes in rheumatoid arthritis following TNF-α stimulation

This study examined the expression of the inhibitory receptor, leucocyte-associated immunoglobulin (Ig)-like receptor-1 (LAIR-1) in fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) patients to investigate its potential role in the modulation of inflammatory cytokines, matrix metalloproteinases (MMPs) and invasiveness of synoviocytes. LAIR-1 expression in synovial tissues from RA patients, osteoarthritis patients and healthy donors was analysed by immunohistochemistry. The membrane-bound form (mLAIR-1) was detected by flow cytometry. Factors involved in inflammation and MMP activity in FLS were analysed by quantitative polymerase chain reaction (qPCR). LAIR-1 expression was higher in the synovia of the RA patients than those of the osteoarthritis patients. Co-immunostaining of vimentin/LAIR-1 demonstrated that LAIR-1 was localized mainly in FLS in the RA patients. Surprisingly, primary FLS isolated from the RA patients had low levels of mLAIR-1 expression, with cytoplasmic distribution. The extracellular domain of LAIR-1 was shed from the cell surface in response to tumour necrosis factor (TNF)-α, and this process could be blocked by serine protease inhibitors. Additional experiments indicated that LAIR-1 over-expression reduced FLS invasion considerably, which reduced simultaneously the mRNA levels of interleukin (IL)-6, IL-8 and MMP-13 in the presence of TNF-α. Our study demonstrated that LAIR-1 is an anti-inflammatory molecule, and was up-regulated in FLS in the RA patients; however, cell-surface LAIR-1 could be shed from cells in the inflammatory microenvironment in RA. This may weaken the interaction of LAIR-1 with its ligand, thus reducing the anti-inflammatory effects of LAIR-1. These findings suggested that LAIR-1 may be an important factor involved in the mediation of the progressive joint destruction in RA.

The risk factors of 9-year follow-up on hypertension in middle-aged people in Tujia-Nationality settlement of China

The aim of this study was to investigate the risk factors of hypertension in middle-aged people within the Tujia-Nationality settlement in China. Demographics questionnaires and fitness tests were performed to identify the risk factors of hypertension in middle-aged people in the years 2005, 2010 and 2014 in the area of southwest Hubei of China. Of the 2428 participants, 568 were classified as hypertensive, giving an overall occurrence of hypertension at 23.4%, and the prevalence of hypertension was the highest in the year 2014 (34.9%). Furthermore, Tujia minority had a significantly higher risk for having hypertension (odds ratio=1.055 with 95% confidence interval (CI): 1.039-1.072; P=0.001) than Han people. Individuals with the lowest level of cardiorespiratory fitness (CRF) had a 2.483-fold risk for hypertension (95% CI, 1.530-4.031; P=0.001). Obesity and overweight individuals increased the risk by 3.470-fold and 2.124-fold, respectively, for having hypertension compared to normal weight people. Finally, white-collar workers had a 58.1 and 31.8% higher risk for hypertension than blue-collar workers in rural and urban areas, respectively. These results demonstrated that the prevalence of hypertension was higher between 2011 and 2014 in the area. The main risk factors for developing hypertension were found to be sex (as woman), Tujia minority, white-collar workers, overweight-obese, those with a middle school education, and those with the lowest CRF.

Imaging findings of adrenal primitive neuroectodermal tumors: a series of seven cases

OBJECTIVE

To explore the imaging features of adrenal primitive neuroectodermal tumors (PNETs).

MATERIALS AND METHODS

This retrospective study included seven patients with surgically and pathologically confirmed adrenal PNETs. Among them, six underwent computed tomography (CT) scans, and one underwent magnetic resonance imaging. The imaging findings, including size, shape, margin, hemorrhage, calcification, cystic degeneration, regional lymph nodes involvement, tumor thrombus formation and enhancement pattern, were retrospectively analyzed.

RESULTS

Among the seven adrenal PNET patients, six were male, and one was female. The median age was 26 years (range 2-56 years). The disease generally presented with either insidious symptoms (n = 4) or non-specific symptoms, including right flank pain (n = 1) and left upper abdominal discomfort (n = 2). On the pre-enhanced CT images, the tumor usually appeared as a well-defined, rounded or oval, heterogeneous mass without calcification. Certain tissue characteristics, such as cystic degeneration (n = 5), capsule (n = 4) and hemorrhage (n = 2), were observed. Regional lymph node involvement was observed in three cases, and renal vein thrombus was observed in one case. All cases showed mild heterogeneous enhancement of the tumor on the enhanced CT images.

CONCLUSION

An adrenal PNET commonly presents as a relatively large, well-defined, heterogeneous mass with cystic degeneration, necrosis and a characteristic mild contrast-enhancement pattern on multiphase enhanced images. PNET should be considered when the diagnosis of common tumors is not favored by signs on images.

CLINICAL TRIAL REGISTRATION STATEMENT

This study was approved by the medical ethics committee of Xiangya Hospital, Central South University. The approval number is 201512538.

CD19+ B cell subsets in the peripheral blood and skin lesions of psoriasis patients and their correlations with disease severity

T lymphocytes are important in the pathogenesis of psoriasis, and increasing evidence indicates that B cells also play an important role. The mechanisms of action, however, remain unclear. We evaluated the ratios of CD19+ B cells in peripheral blood mononuclear cells (PBMCs) from 157 patients with psoriasis (65 patients with psoriasis vulgaris, 32 patients with erythrodermic psoriasis, 30 patients with arthropathic psoriasis, and 30 patients with pustular psoriasis) and 35 healthy controls (HCs). Ratios of CD19+ B cells in skin lesions were compared with non-lesions in 7 erythrodermic psoriasis patients. The Psoriasis Area Severity Index (PASI) was used to measure disease severity. CD19+ B cell ratios in PBMCs from psoriasis vulgaris (at both the active and stationary stage) and arthropathic psoriasis patients were higher compared with HCs (P<0.01), but ratios were lower in erythrodermic and pustular psoriasis patients (P<0.01). CD19+ B cell ratios in erythrodermic psoriasis skin lesions were higher than in non-lesion areas (P<0.001). Different subsets of CD19+CD40+, CD19+CD44+, CD19+CD80+, CD19+CD86+, CD19+CD11b+, and CD19+HLA-DR+ B cells in PBMCs were observed in different psoriasis clinical subtypes. PASI scores were positively correlated with CD19+ B cell ratios in psoriasis vulgaris and arthropathic psoriasis cases (r=0.871 and r=0.692, respectively, P<0.01), but were negatively correlated in pustular psoriasis (r=-0.569, P<0.01). The results indicated that similar to T cells, B cells activation may also play important roles in different pathological stages of psoriasis.

Demonstration of a near-IR line-referenced electro-optical laser frequency comb for precision radial velocity measurements in astronomy

An important technique for discovering and characterizing planets beyond our solar system relies upon measurement of weak Doppler shifts in the spectra of host stars induced by the influence of orbiting planets. A recent advance has been the introduction of optical frequency combs as frequency references. Frequency combs produce a series of equally spaced reference frequencies and they offer extreme accuracy and spectral grasp that can potentially revolutionize exoplanet detection. Here we demonstrate a laser frequency comb using an alternate comb generation method based on electro-optical modulation, with the comb centre wavelength stabilized to a molecular or atomic reference. In contrast to mode-locked combs, the line spacing is readily resolvable using typical astronomical grating spectrographs. Built using commercial off-the-shelf components, the instrument is relatively simple and reliable. Proof of concept experiments operated at near-infrared wavelengths were carried out at the NASA Infrared Telescope Facility and the Keck-II telescope.

Laser frequency combs emit a spectrum of equally spaced peaks that can provide precise frequency references useful for astronomy. Here, the authors demonstrate a frequency comb using electro-optical modulation, which has a line spacing that is resolvable using grating spectrographs unlike the mode-locking approach.

Non-invasive prenatal testing for trisomies 21, 18 and 13: clinical experience from 146,958 pregnancies

OBJECTIVES

To report the clinical performance of massively parallel sequencing-based non-invasive prenatal testing (NIPT) in detecting trisomies 21, 18 and 13 in over 140,000 clinical samples and to compare its performance in low-risk and high-risk pregnancies.

METHODS

Between 1 January 2012 and 31 August 2013, 147,314 NIPT requests to screen for fetal trisomies 21, 18 and 13 using low-coverage whole-genome sequencing of plasma cell-free DNA were received. The results were validated by karyotyping or follow-up of clinical outcomes.

RESULTS

NIPT was performed and results obtained in 146,958 samples, for which outcome data were available in 112,669 (76.7%). Repeat blood sampling was required in 3213 cases and 145 had test failure. Aneuploidy was confirmed in 720/781 cases positive for trisomy 21, 167/218 cases positive for trisomy 18 and 22/67 cases positive for trisomy 13 on NIPT. Nine false negatives were identified, including six cases of trisomy 21 and three of trisomy 18. The overall sensitivity of NIPT was 99.17%, 98.24% and 100% for trisomies 21, 18 and 13, respectively, and specificity was 99.95%, 99.95% and 99.96% for trisomies 21, 18 and 13, respectively. There was no significant difference in test performance between the 72,382 high-risk and 40,287 low-risk subjects (sensitivity, 99.21% vs. 98.97% (P = 0.82); specificity, 99.95% vs. 99.95% (P = 0.98)). The major factors contributing to false-positive and false-negative NIPT results were maternal copy number variant and fetal/placental mosaicism, but fetal fraction had no effect.

CONCLUSIONS

Using a stringent protocol, the good performance of NIPT shown by early validation studies can be maintained in large clinical samples. This technique can provide equally high sensitivity and specificity in screening for trisomy 21 in a low-risk, as compared to high-risk, population.

Serum amyloid A induces interleukin-1β secretion from keratinocytes via the NACHT, LRR and PYD domains-containing protein 3 inflammasome

Interleukin (IL)-1β is now emerging as a critical cytokine in the pathogenesis of T helper type 17 (Th17)-mediated skin diseases, including psoriasis. Psoriatic keratinocytes are a major source of IL-1β; however, the mechanisms triggering IL-1β processing remain unknown. Recently, an acute-phase protein serum amyloid A (SAA) has been identified as a danger signal that triggers inflammasome activation and IL-1β secretion. In this study, we detected increased SAA mRNA and protein expression in psoriatic epidermis. In cultured keratinocytes, SAA up-regulated the expression of pro-IL-1β and secretion of mature IL-1β. On the transcriptional level, blocking Toll-like receptor-2 (TLR-2), TLR-4 or nuclear factor kappa B (NF-κB) attenuated SAA-induced expression of IL-1β mRNA. SAA up-regulated caspase-1 and NACHT, LRR and PYD domains-containing protein 3 (NLRP3) expression in keratinocytes. Inhibiting caspase-1 activity and silencing NLRP3 decreased IL-1β secretion, confirming NLRP3 as the SAA-responsive inflammasome on the post-transcriptional level. The mechanism of SAA-triggered NLRP3 activation and subsequent IL-1β secretion was found to involve the generation of reactive oxygen species. Finally, the expression of SAA by keratinocytes was up-regulated by IL-17A. Taken together, our results indicate that keratinocyte-derived SAA triggers a key inflammatory mediator, IL-1β, via NLRP3 inflammasome activation, providing new potential targets for the treatment of this chronic skin disease.

Analysis of the electrostatics in DyIII single-molecule magnets: the case study of Dy(Murex)3

A Dy^III-based single-molecule magnet is reported. Ab initio calculations highlight that molecular symmetry plays a predominant role over site symmetry in determining the shape and orientation of Dy^III magnetic anisotropy.