In-Situ Self-Assembly Dipole Shielding Layer Toward Efficient and Stable Inorganic Perovskite Solar Cells.

Despite CsPbI2.75Br0.25 inorganic perovskites exhibit high potential for single-junction and/or tandem solar cells, unexpected non-radiative recombination, and mismatched interfacial band alignment within the inorganic perovskite solar cells (PSCs) disadvantageously affect their photovoltaic performance. Rational design of the dipole shielding layer (DSL) is vital to realize a win-win situation for the defect passivation and band alignment. Herein, A-site dipole molecules, that is, neopentylamine and 2-methylbutylamine, are employed for in-situ self-assembly of a thus-far unreported DSL at the interface between 3D perovskite and hole transport layer. The as-prepared DSL demonstrates a 2D RP phase perovskite and the lattice-matching structurally-stable DSL@3D perovskite enables to alleviate the unexpected surface defects and suppress the spontaneous non-radiative recombination by means of effectively tuning the surface work function via regulating the dipole moment length and Van der Waals gap. Accordingly, the top dipole-modified inorganic PSCs exhibit a champion power conversion efficiency (PSC) as high as 19.77% and a fill factor over 83%. Equally importantly, the corresponding solar cells demonstrate a remarkable enhanced stability, maintaining 90% of its initial efficiency for more than 1200 h without encapsulation under a 20% ± 5% relative humidity.

Emerging lead-free all inorganic perovskite single crystals K7Bi3X16 (X = Cl, Br) toward photodetector application.

Lead-free inorganic perovskites have attracted intensive attention in the field of photodetectors owing to their high stability, non-toxicity, and remarkable photoelectric characteristics. Herein, we designed and developed a series of thus-far unreported lead-free all inorganic perovskite single crystals, K7Bi3X16 (X = Cl, Br). In particular, we resorted to cooling crystallization and intercalated K+ to inorganic Bi-Br and Bi-Cl frameworks as inorganic A-site cations, obtaining zero-dimensional (0D) K7Bi3X16 (X = Cl, Br) perovskite single crystals, which display suitable bandgaps, excellent electron mobility and low trap-state density, as analysed by experimental characterization and density functional theory (DFT) calculations. Accordingly, the vertical structure K7Bi3Br16 photodetector can achieve a fast ON/OFF switch under the irradiation of 395 nm light. When the light intensity is 5 mW cm-2 and the voltage is 3 V, the responsivity is calculated to be 0.052 mA W-1. The above characteristics make K7Bi3Br16 a promising material for fabricating ultraviolet photodetectors.

Use of interrupted time-series analyses in evaluating health economic outcomes following implementation of multilayer water-tight wound closure in a primary total joint arthroplasty population.

Aim: Total joint arthroplasty (TJA) with multi-layer, watertight closure (MLWC) using knotless barbed suture and 2-octyl cyanoacrylate plus polymer mesh tape was compared with conventional closure (CC) using Vicryl™ sutures and staples. Patients & methods: Electronic medical records of patients undergoing TJA (1574: total knee arthroplasty; 580: total hip arthroplasty; 13: unknown) from a single surgeon at a US hospital (CC 2011 to 2013; MLWC 2015 to 2020) were reviewed. Outcomes were length of stay (LOS), discharge to skilled nursing facility (SNF), 90-day surgical site infection (SSI) and 90-day readmission. Logistic regression controlled for baseline characteristics. Adjusted interrupted time series (ITS) analyses accounted for decreasing trends in LOS and SNF discharge over time. Results: Among 2167 TJA cases (mean [standard deviation] age 66.0 [9.7] years, 53.3% female), 906 received CC and 1261 received MLWC. Bivariate analysis showed no statistically significant differences in 90-day SSI rates; however, MLWC patients had 60% lower 90-day readmission rates (1.5 vs 3.8%, p < 0.05), 44% lower LOS (1.4 vs 2.5 days, p < 0.05) and 40% lower discharge rates to a skilled care facility (8.5 vs 14.1%, p < 0.05). Multivariable analyses showed CC patients were 2.45-times more likely to be readmitted within 90 days, 1.88-times more likely to be discharged to SNF and had 1.67-times longer LOS compared with MLWC. ITS analyses showed a sharp decline in LOS (0.9 days) and discharge to SNF (5.6% incidence) after implementation of MLWC, followed by no further changes for the remainder of the study period. Conclusion: MLWC was associated with ≥40% reduction in 90-day readmission, LOS and SNF discharge compared with TJA CC. LOS and discharge rate to SNF declined sharply after the implementation of MLWC.

Saturation transfer properties of tumour xenografts derived from prostate cancer cell lines 22Rv1 and DU145.

Histopathology is currently the most reliable tool in assessing the aggressiveness and prognosis of solid tumours. However, developing non-invasive modalities for tumour evaluation remains crucial due to the side effects and complications caused by biopsy procedures. In this study, saturation transfer MRI was used to investigate the microstructural and metabolic properties of tumour xenografts in mice derived from the prostate cancer cell lines 22Rv1 and DU145, which express different aggressiveness. The magnetization transfer (MT) and chemical exchange saturation transfer (CEST) effects, which are associated with the microstructural and metabolic properties in biological tissue, respectively, were analyzed quantitatively and compared amongst different tumour types and regions. Histopathological staining was performed as a reference. Higher cellular density and metabolism expressed in more aggressive tumours (22Rv1) were associated with larger MT and CEST effects. High collagen content in the necrotic regions might explain their higher MT effects compared to tumour regions.

On-site generated metal organic framework-deriving core/shell ZnCo2O4/ZnO nanoarray for better water oxidation.

The high cost and elemental scarcity of precious metals has triggered a search for non-noble-metal catalysts for the oxygen evolution reaction (OER) process. Herein, with the assistance of metal organic frameworks (MOFs), a core/shell ZnCo2O4/ZnO nanoarray with an amorphous carbon protecting layer, grown on carbon fiber, was in situ topologically generated. The resulting catalyst shows much enhanced OER performance under alkaline condition, requiring as low as 279 mV of overpotential to reach 10 mA cm-2 current density. Our work may open up a new way for exploiting MOF-derived non-noble-metal electrocatalysts for various electrochemical applications.

Estimation of thyroid volume from scintigraphy through 2D/3D registration of a statistical shape model.

Accurate measurement of thyroid volume is important for thyroid disease diagnosis and therapy. In nuclear medicine, the thyroid volume is usually estimated from scintigraphy images using empirical equations. However, due to the lack of volumetric information from the scintigraphy image, the accuracy of equation-based estimation is imperfect. To solve this problem, this paper proposes a method which registers a 3D thyroid statistical shape model (SSM) to a single-view scintigraphy image to achieve more accurate volume estimation. The SSM was constructed based on a training set of segmented 3D CT images, and the thyroid shape variations between the training subjects were modelled using the point distribution model. For thyroid volume estimation, the SSM was projected into the scintigraphy image of the target patient, and then the projected model shape was nonrigidly registered with the patient's scintigraphy image. The resultant 2D deformation file was back-projected to 3D space to guide the deformation of the 3D SSM. This process was repeated iteratively until convergence, and the volume of the finally deformed SSM was considered as the estimation of the patient's thyroid volume. For validation, this method was evaluated based on a test set of 20 scintigraphy images, achieving an estimation error of -2.10% ± 5.20% which was much less than the error of the conventional equation-based method (35.76% ± 15.20%) based on the same test set. The robustness of this method was further tested using a challenging case, i.e. a scintigraphy image with a large thyroid tumor. For this case, the volume estimation error was only 6.08%. Our method has significantly improved the accuracy of thyroid volume estimation from scintigraphy images, and it will enhance the value of scintigraphy imaging for thyroid disease diagnosis and radioiodine therapy.

Correction to: Metabolic Brain Network Analysis of Hypothyroidism Symptom Based on [18F]FDG-PET of Rats.

This article was updated to correct the spelling of Hongkai Wang's name: it is correct as displayed here.

Deformable torso phantoms of Chinese adults for personalized anatomy modelling.

In recent years, there has been increasing demand for personalized anatomy modelling for medical and industrial applications, such as ergonomics device development, clinical radiological exposure simulation, biomechanics analysis, and 3D animation character design. In this study, we constructed deformable torso phantoms that can be deformed to match the personal anatomy of Chinese male and female adults. The phantoms were created based on a training set of 79 trunk computed tomography (CT) images (41 males and 38 females) from normal Chinese subjects. Major torso organs were segmented from the CT images, and the statistical shape model (SSM) approach was used to learn the inter-subject anatomical variations. To match the personal anatomy, the phantoms were registered to individual body surface scans or medical images using the active shape model method. The constructed SSM demonstrated anatomical variations in body height, fat quantity, respiratory status, organ geometry, male muscle size, and female breast size. The masses of the deformed phantom organs were consistent with Chinese population organ mass ranges. To validate the performance of personal anatomy modelling, the phantoms were registered to the body surface scan and CT images. The registration accuracy measured from 22 test CT images showed a median Dice coefficient over 0.85, a median volume recovery coefficient (RCvlm ) between 0.85 and 1.1, and a median averaged surface distance (ASD) < 1.5 mm. We hope these phantoms can serve as computational tools for personalized anatomy modelling for the research community.

Metabolic Brain Network Analysis of Hypothyroidism Symptom Based on [18F]FDG-PET of Rats.

PURPOSE: Recent researches have demonstrated the value of using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron emission tomography (PET) imaging to reveal the hypothyroidism-related damages in local brain regions. However, the influence of hypothyroidism on the entire brain network is barely studied. This study focuses on the application of graph theory on analyzing functional brain networks of the hypothyroidism symptom. PROCEDURES: For both the hypothyroidism and the control groups of Wistar rats, the functional brain networks were constructed by thresholding the glucose metabolism correlation matrices of 58 brain regions. The network topological properties (including the small-world properties and the nodal centralities) were calculated and compared between the two groups. RESULTS: We found that the rat brains, like human brains, have typical properties of the small-world network in both the hypothyroidism and the control groups. However, the hypothyroidism group demonstrated lower global efficiency and decreased local cliquishness of the brain network, indicating hypothyroidism-related impairment to the brain network. The hypothyroidism group also has decreased nodal centrality in the left posterior hippocampus, the right hypothalamus, pituitary, pons, and medulla. This observation accorded with the hypothyroidism-related functional disorder of hypothalamus-pituitary-thyroid (HPT) feedback regulation mechanism. CONCLUSION: Our research quantitatively confirms that hypothyroidism hampers brain cognitive function by causing impairment to the brain network of glucose metabolism. This study reveals the feasibility and validity of applying graph theory method to preclinical [18F]FDG-PET images and facilitates future study on human subjects.