High-Throughput Estimation of Phonon Thermal Conductivity from First-Principles Calculations of Elasticity.

Thermal conductivity is a crucial property for thermal management of modern electronics, thermal energy conversion, and energy sustainable development. However, it is very expensive and time-consuming to calculate the phonon thermal conductivity of materials through the fully ab initio calculations or molecular dynamics simulations. Exploiting the fundamental correlation between elastic properties (bulk and shear modulus) and phonon thermal conductivity of crystalline materials, we develop an efficient method, phonon-elasticity-thermal (PET) model to rapidly and accurately estimate the phonon thermal conductivity at the high-temperature limit based on the Born-von Karman periodic boundary condition and Umklapp phonon-phonon scattering relaxation time approximation. As a demonstration, we calculate the phonon thermal conductivities of 226 inorganic solid materials covering the whole 7 crystalline systems within a high-throughput calculation framework on account of our PET model. The high-throughput prediced phonon thermal conductivities is in good agreement with experimental measurements. Our results imply the potential application of the elasticity-based phonon thermal conductivity estimation to screen or guide the material discovery of target phonon thermal conductivity and also provide a reference for the study of phonon-elasticity-thermal relationship.

Deep Learning based Retinal Vessel Caliber Measurement and the Association with Hypertension.

PURPOSE: To develop a highly efficient and fully automated method that measures retinal vessel caliber using digital retinal photographs and evaluate the association between retinal vessel caliber and hypertension. METHODS: The subjects of this study were from two sources in Beijing, China, a hypertension case-control study from Tongren Hospital (Tongren study) and a community-based atherosclerosis cohort from Peking University First Hospital (Shougang study). Retinal vessel segmentation and arteriovenous classification were achieved simultaneously by a customized deep learning model. Two experienced ophthalmologists evaluated whether retinal vessels were correctly segmented and classified. The ratio of incorrectly segmented and classified retinal vessels was used to measure the accuracy of the model's recognition. Central retinal artery equivalents, central retinal vein equivalents and arteriolar-to-venular diameter ratio were computed to analyze the association between retinal vessel caliber and the risk of hypertension. The association was then compared to that derived from the widely used semi-automated software (Integrative Vessel Analysis). RESULTS: The deep learning model achieved an arterial recognition error rate of 1.26%, a vein recognition error rate of 0.79%, and a total error rate of 1.03%. Central retinal artery equivalents and arteriolar-to-venular diameter ratio measured by both Integrative Vessel Analysis and deep learning methods were inversely associated with the odds of hypertension in both Tongren and Shougang studies. The comparisons of areas under the receiver operating characteristic curves from the proposed deep learning method and Integrative Vessel Analysis were all not significantly different (p > .05). CONCLUSION: The proposed deep learning method showed a comparable diagnostic value to Integrative Vessel Analysis software. Compared with semi-automatic software, our deep learning model has significant advantage in efficiency and can be applied to population screening and risk evaluation.

Semi-Supervised Dual Stream Segmentation Network for Fundus Lesion Segmentation.

Accurate segmentation of retinal images can assist ophthalmologists to determine the degree of retinopathy and diagnose other systemic diseases. However, the structure of the retina is complex, and different anatomical structures often affect the segmentation of fundus lesions. In this paper, a new segmentation strategy called a dual stream segmentation network embedded into a conditional generative adversarial network is proposed to improve the accuracy of retinal lesion segmentation. First, a dual stream encoder is proposed to utilize the capabilities of two different networks and extract more feature information. Second, a multiple level fuse block is proposed to decode the richer and more effective features from the two different parallel encoders. Third, the proposed network is further trained in a semi-supervised adversarial manner to leverage from labeled images and unlabeled images with high confident pseudo labels, which are selected by the dual stream Bayesian segmentation network. An annotation discriminator is further proposed to reduce the negativity that prediction tends to become increasingly similar to the inaccurate predictions of unlabeled images. The proposed method is cross-validated in 384 clinical fundus fluorescein angiography images and 1040 optical coherence tomography images. Compared to state-of-the-art methods, the proposed method can achieve better segmentation of retinal capillary non-perfusion region and choroidal neovascularization.

Silencing of the chemokine CXC receptor 4 (CXCR4) hampers cancer progression and increases cisplatin (DDP)-sensitivity in clear cell renal cell carcinoma (ccRCC).

Aberrant expression of the chemokine CXC receptor 4 (CXCR4) is closely associated with cancer progression and drug-resistance in multiple cancers, and we first investigated the role of CXCR4 in regulating cancer pathogenesis and cisplatin (DDP)-resistance in clear cell renal cell carcinoma (ccRCC) in the present study. Here, we identified that CXCR4 acted as an oncogene to promote cancer progression and genetically silencing of CXCR4 increased cisplatin (DDP)-sensitivity in ccRCC in vitro and in vivo. Functionally, analysis from the clinical and cellular data indicated that CXCR4 was significantly upregulated in ccRCC tissues and cells, compared to their normal counterparts. Next, the loss-of-function experiments validated that knock-down of CXCR4 suppressed cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) in ccRCC cells, while CXCR4 overexpression had opposite effects on the above cellular functions. Consistently, the xenograft tumor-bearing mice models were established, and the results supported that knock-down of CXCR4 inhibited tumor growth and the expression levels of Ki67 protein in vivo. In addition, the ccRCC cells were exposed to DDP treatment, and we surprisingly found that upregulation of CXCR4 increased DDP-resistance in ccRCC cells, and conversely, CXCR4 ablation sensitized ccRCC cells to DDP stimulation. Taken together, we concluded that CXCR4 ablation hindered cancer progression and enhanced DDP-sensitivity in ccRCC, and the present study identified a novel therapeutic biomarker for ccRCC.

In vivo fluorescence molecular imaging of the vascular endothelial growth factor in rats with early diabetic retinopathy.

Anti-vascular endothelial growth factor (anti-VEGF) therapy is effective for reducing the severity level of diabetic retinopathy (DR). However, it is difficult to determine the in vivo spatial and temporal expression of VEGF in the DR retina at an early stage. Here, we report a quantitatively fluorescence molecular imaging and image analysis method by creating a VEGF targeted fluorescence imaging probe, which can potentially detect and predict anti-VEGF treatment response. Moreover, the ex vivo multiscale fluorescence imaging demonstrated the spatial correlation between VEGF relative expression and vascular abnormalities in two and three dimensions. It revealed that VEGF was mainly abnormally expressed at the bifurcation of the microvessels, which advances the knowledge of the DR progression by molecular fluorescence imaging. Our study has the potential to achieve early detection of DR disease, provide more insight into understanding anti-VEGF treatment, and may help stratify patients based on the molecular imaging of retinal VEGF.

Subthreshold micropulse laser photocoagulation therapy in a case of bilateral retinal astrocytic hamartomas with tuberous sclerosis complex: A case report.

RATIONALE: Report a case of bilateral multiple retinal hamartomas (RAHs) in a patient with tuberous sclerosis complex (TSC) and introduced a new method (subthreshold micropulse laser photocoagulation) for the treatment of RAHs. PATIENT CONCERNS: A 20-year-old man with TSC complained of decreased vision and metamorphosia in both eyes for 2 months. At presentation, visual acuity (VA) was 20/32 in the right eye and 20/40 in the left eye. Fundus photographs, optical coherence tomography, fundus fluorescein angiography (FFA), and indocyanine green angiography indicated multiple RAHs in both eyes. DIAGNOSES: Bilateral retinal astrocytic hamartomas. INTERVENTIONS: In the right eye, 577 nm photocoagulation was adopted to treat the RAHs with obvious fluorescein leakage in FFA. The paramacular RAHs were treated by subthreshold micropulse mode to minimize the damage to macula. Photocoagulation therapy was administrated in the left eye after 1 dose of intravitreal ranibizumab treatment. OUTCOMES: After photocoagulation therapy (including subthreshold micropulse laser photocoagulation for the paramacular RAHs in both eyes), the VA improved to 20/25 OD and 20/32 OS with no recurrence of exudation. LESSONS: About 577 nm photocoagulation for the peripheral RAHs in combination with subthreshold micropulse laser photocoagulation for RAHs in the macular zone is a good option for multiple RAHs in patients with TSC.

The effect of lens aging and cataract surgery on circadian rhythm.

Many organisms have evolved an approximately 24-hour circadian rhythm that allows them to achieve internal physiological homeostasis with external environment. Suprachiasmatic nucleus (SCN) is the central pacemaker of circadian rhythm, and its activity is entrained to the external light-dark cycle. The SCN controls circadian rhythm through regulating the synthesis of melatonin by pineal gland via a multisynaptic pathway. Light, especially short-wavelength blue light, is the most potent environmental time cue in circadian photoentrainment. Recently, the discovery of a novel type of retinal photoreceptors, intrinsically photosensitive retinal ganglion cells, sheds light on the mechanism of circadian photoentrainment and raises concerns about the effect of ocular diseases on circadian system. With age, light transmittance is significantly decreased due to the aging of crystalline lens, thus possibly resulting in progressive loss of circadian photoreception. In the current review, we summarize the circadian physiology, highlight the important role of light in circadian rhythm regulation, discuss about the correlation between age-related cataract and sleep disorders, and compare the effect of blue light- filtering intraocular lenses (IOLs) and ultraviolet only filtering IOLs on circadian rhythm.