We report two cases of endothelial corneal allograft rejection following immunisation with SARS-CoV-2 messenger RNA (mRNA) vaccine BNT162b2 and describe the implications for management of transplant ...recipients postvaccination for COVID-19.
A 66-year-old woman with Fuchs endothelial corneal dystrophy (FECD) and a unilateral Descemet's membrane endothelial keratoplasty (DMEK) transplant received COVID-19 mRNA vaccine BNT162b2 14 days post-transplant. Seven days later, she presented with symptoms and signs of endothelial graft rejection. An 83-year-old woman with bilateral DMEK transplants for FECD 3 and 6 years earlier developed simultaneous acute endothelial rejection in both eyes, 3 weeks post second dose of COVID-19 mRNA vaccine BNT162b2. Rejection in both cases was treated successfully with topical corticosteroids.
We believe this is the first report of temporal association between corneal transplant rejection following immunisation against COVID-19 and the first report of DMEK rejection following any immunisation. We hypothesise that the allogeneic response may have been initiated by the host antibody response following vaccination. Clinicians and patients should be aware of the potential of corneal graft rejection associated with vaccine administration and may wish to consider vaccination in advance of planned non-urgent keratoplasties. Patients should be counselled on the symptoms and signs that require urgent review to allow early treatment of any confirmed rejection episode.
Strongly coupled Nafion molecules and ordered porous CdS networks are fabricated for visible‐light photoelectrochemical (PEC) hydrogen evolution. The Nafion layer coating shifts the band position of ...CdS upward and accelerates charge transfer in the photoelectrode/electrolyte interface. It is highly expected that the strong coupling effect between organic and inorganic materials will provide new routes to advance PEC water splitting.
The unprecedented early spring frost that appears as a cold stress adversely affects growth and productivity in tea (
L.); therefore, it is indispensable to develop approaches to improve the cold ...tolerance of tea. Here, we investigated the effect of pretreatment with exogenous melatonin on the net photosynthetic rate, the maximum photochemical efficiency of PSII, chlorophyll content, lipid peroxidation, reactive oxygen species (ROS) accumulation, antioxidant potential, and redox homeostasis in leaves of tea plants following cold stress. Our results revealed that cold treatment induced oxidative stress by increasing ROS accumulation, which in turn affected the photosynthetic process in tea leaves. However, treatment with melatonin mitigated cold-induced reductions in photosynthetic capacity by reducing oxidative stress through enhanced antioxidant potential and redox homeostasis. This study provides strong evidence that melatonin could alleviate cold-induced adverse effects in tea plants.
•TRPV6 is a vitamin D-regulated Ca2+-selective channel required for Ca2+ homeostasis.•TRPV6 mediates the first step in the transcellular Ca2+ transport pathway.•TRPV6 is required for mammalian male ...fertility and maternal-fetal transport of Ca2+.•Mutations compromising TRPV6 function cause transient neonatal hyperparathyroidism.•TRPV6 dysfunction is linked to chronic pancreatitis and cancer aggressiveness.
Calcium-selective channel TRPV6 (Transient Receptor Potential channel family, Vanilloid subfamily member 6) belongs to the TRP family of cation channels and plays critical roles in transcellular calcium (Ca2+) transport, reuptake of Ca2+ into cells, and maintaining a local low Ca2+ environment for certain biological processes. Recent crystal and cryo-electron microscopy-based structures of TRPV6 have revealed mechanistic insights on how the protein achieves Ca2+ selectivity, permeation, and inactivation by calmodulin. The TRPV6 protein is expressed in a range of epithelial tissues such as the intestine, kidney, placenta, epididymis, and exocrine glands such as the pancreas, prostate and salivary, sweat, and mammary glands. The TRPV6 gene is a direct transcriptional target of the active form of vitamin D and is efficiently regulated to meet the body’s need for Ca2+ demand. In addition, TRPV6 is also regulated by the level of dietary Ca2+ and under physiological conditions such as pregnancy and lactation. Genetic models of loss of function in TRPV6 display hypercalciuria, decreased bone marrow density, deficient weight gain, reduced fertility, and in some cases alopecia. The models also reveal that the channel plays an indispensable role in maintaining maternal-fetal Ca2+ transport and low Ca2+ environment in the epididymal lumen that is critical for male fertility. Most recently, loss of function mutations in TRPV6 gene is linked to transient neonatal hyperparathyroidism and early onset chronic pancreatitis. TRPV6 is overexpressed in a wide range of human malignancies and its upregulation is strongly correlated to tumor aggressiveness, metastasis, and poor survival in selected cancers. This review summarizes the current state of knowledge on the expression, structure, biophysical properties, function, polymorphisms, and regulation of TRPV6. The aberrant expression, polymorphisms, and dysfunction of this protein linked to human diseases are also discussed.
Coronavirus Disease 2019 (COVID-19) spread globally in early 2020, causing the world to face an existential health crisis. Automated detection of lung infections from computed tomography (CT) images ...offers a great potential to augment the traditional healthcare strategy for tackling COVID-19. However, segmenting infected regions from CT slices faces several challenges, including high variation in infection characteristics, and low intensity contrast between infections and normal tissues. Further, collecting a large amount of data is impractical within a short time period, inhibiting the training of a deep model. To address these challenges, a novel COVID-19 Lung Infection Segmentation Deep Network ( Inf-Net ) is proposed to automatically identify infected regions from chest CT slices. In our Inf-Net , a parallel partial decoder is used to aggregate the high-level features and generate a global map. Then, the implicit reverse attention and explicit edge-attention are utilized to model the boundaries and enhance the representations. Moreover, to alleviate the shortage of labeled data, we present a semi-supervised segmentation framework based on a randomly selected propagation strategy, which only requires a few labeled images and leverages primarily unlabeled data. Our semi-supervised framework can improve the learning ability and achieve a higher performance. Extensive experiments on our COVID-SemiSeg and real CT volumes demonstrate that the proposed Inf-Net outperforms most cutting-edge segmentation models and advances the state-of-the-art performance.
This study proposed two pedotransfer functions (PTFs) to estimate sandy soil water retention curves. It is based on the van Genuchten's water retention model and from a semiphysical and ...semistatistical approach. Basic gradation parameters of
d60 as particle size at 60% passing and the coefficient of uniformity
Cu are employed in the PTFs with two idealized conditions, the monosized scenario and the extremely polydisperse condition, satisfied. Water retention tests are carried out on eight granular materials with narrow particle size distributions as supplementary data of the UNSODA database. The air entry value is expressed as inversely proportional to
d60 and the parameter
n, which is related to slope of water retention curve, is a function of
Cu. The proposed PTFs, although have fewer parameters, have better fitness than previous PTFs for sandy soils. Furthermore, by incorporating with the suction stress definition, the proposed pedotransfer functions are imbedded in shear strength equations which provide a way to estimate capillary induced tensile strength or cohesion at a certain suction or degree of saturation from basic soil gradation parameters. The estimation shows quantitative agreement with experimental data in literature, and it also explains that the capillary‐induced cohesion is generally higher for materials with finer mean particle size or higher polydispersity.
Key Points
Pedotransfer functions are proposed to estimate WRC from two basic soil gradation parameters (d10 and Cu) through a semiempirical approach
With physical features considered, the model with fewer and more easily obtained parameters shows good performance in WRC prediction
By incorporating with the suction stress definition, it provides a preliminary estimation of strength properties from grain size
Estimating hydraulic conductivity from particle size distribution (PSD) is an important issue for various engineering problems. Classical models such as Hazen model, Beyer model, and Kozeny‐Carman ...model usually regard the grain diameter at 10% passing (
d10) as an effective grain size and the effects of particle size uniformity (in Beyer model) or porosity (in Kozeny‐Carman model) are sometimes embedded. This technical note applies the dimensional analysis (Buckingham's
∏ theorem) to analyze the relationship between hydraulic conductivity and particle size distribution (PSD). The porosity is regarded as a dependent variable on the grain size distribution in unconsolidated conditions. It indicates that the coefficient of grain size uniformity and a dimensionless group representing the gravity effect, which is proportional to the mean grain volume, are the main two determinative parameters for estimating hydraulic conductivity. Regression analysis is then carried out on a database comprising 431 samples collected from different depositional environments and new equations are developed for hydraulic conductivity estimation. The new equation, validated in specimens beyond the database, shows an improved prediction comparing to using the classic models.
Key Points
Dimensional analysis is employed in the analysis of the relationship between hydraulic conductivity and particle size distribution
New equations are proposed for hydraulic conductivity estimation by basic soil gradation parameters
The new method improves the estimation of hydraulic conductivity significantly comparing to classic equations
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