Dynamic Two-Dimensional Covalent Organic Frameworks with Large Solvent-Induced Lattice Expansion.

Dynamic covalent organic frameworks (COFs) can switch reversibly between crystalline phases with different unit cell parameters and porosities upon physisorption of guest molecules. While impressive changes in unit cell volumes have been realized for three-dimensional frameworks, the solvent-induced volume changes of two-dimensional (2D) COFs have remained comparably small. We have now developed a series of 2D COFs where we systematically varied the length of the interconnecting bridge units. The optimized materials achieve solvent-induced expansions of up to 85% relative to the volume of the solvent-free contracted COFs. These structural changes are fully reversible and the frameworks fully retain their high degree of crystalline order. This study introduces a versatile design strategy for dynamic 2D COFs, which could enable future applications of these materials in gas separation and sensing.

Doppler Ultrasound-Guided Filler Injections: Useful Tips to Integrate Ultrasound in Daily Practice.

The development of high-frequency devices and transducers in recent years has enabled the growth of the use of dermatologic ultrasound. Real-time monitoring of the anatomy of the face during the application of aesthetic injectables potentially prevents complications such as vascular occlusions. Injecting physicians starting out in the practice of ultrasound-guided injections are commonly faced with practical questions about its use. In this article, based on the experience with ultrasound-guided filler injections of 2 large clinical centers in 2 countries, the authors summarize the steps involved when setting out to use ultrasound to guide injectable aesthetic procedures, such as fillers and biostimulators. First, the authors discuss factors that guide the choice of equipment and ultrasound transducers to perform the procedures. Next, a detailed discussion on practical issues related to the procedure is provided. The authors then consider the positioning of operators and equipment in the treatment field. The authors conclude by suggesting 2 possible techniques to guide injectable procedures: (1) scan before injecting or (2) scan while injecting.

Inert Liquid Exfoliation and Langmuir-Type Thin Film Deposition of Semimetallic Metal Diborides.

Graphite is one of only a few layered materials that can be exfoliated into nanosheets with semimetallic properties, which limits the applications of nanosheet-based electrodes to material combinations compatible with the work function of graphene. It is therefore important to identify additional metallic or semimetallic two-dimensional (2D) nanomaterials that can be processed in solution for scalable fabrication of printed electronic devices. Metal diborides represent a family of layered non-van der Waals crystals with semimetallic properties for all nanosheet thicknesses. While previous reports show that the exfoliated nanomaterial is prone to oxidation, we demonstrate a readily accessible inert exfoliation process to produce quasi-2D nanoplatelets with intrinsic material properties. For this purpose, we demonstrate the exfoliation of three representative metal diborides (MgB2, CrB2, and ZrB2) under inert conditions. Nanomaterial is characterized using a combination of transmission electron microscopy, scanning electron microscopy, atomic force microscopy, IR, and UV-vis measurements, with only minimal oxidation indicated postprocessing. By depositing the pristine metal diboride nanoplatelets as thin films using a Langmuir-type deposition technique, the ohmic behavior of the networks is validated. Furthermore, the material decomposition is studied by using a combination of electrical and optical measurements after controlled exposure to ambient conditions. Finally, we report an efficient, low-cost approach for sample encapsulation to protect the nanomaterials from oxidation. This is used to demonstrate low-gauge factor strain sensors, confirming metal diboride nanosheets as a suitable alternative to graphene for electrode materials in printed electronics.

The Pink Doughnut Sign-A Clinical Clue to Recognize Basal Cell Carcinoma Presenting as Chronic Leg Ulcer.

Chronic lower leg ulcers (LLUs) are a very common and associated with a high subjective and economic burden. They can be caused by a variety of factors. We have observed a common clinical feature in patients suffering from LLUs, which ultimately proved to be basal cell carcinomas (BCCs). We have nicknamed this sign "the pink doughnut sign." The pink doughnut sign can aid in the early recognition of such BCCs, which is crucial to prevent unnecessary suffering, treatment costs, and poor local outcomes.

On-water surface synthesis of electronically coupled 2D polyimide-MoS2 van der Waals heterostructure.

The water surface provides a highly effective platform for the synthesis of two-dimensional polymers (2DP). In this study, we present an efficient on-water surface synthesis of crystalline monolayer 2D polyimide (2DPI) through the imidization reaction between tetra (4-aminophenyl) porphyrin (M1) and perylenetracarboxylic dianhydride (M2), resulting in excellent stability and coverage over a large area (tens of cm2). We further fabricate innovative organic-inorganic hybrid van der Waals heterostructures (vdWHs) by combining with exfoliated few-layer molybdenum sulfide (MoS2). High-resolution transmission electron microscopy (HRTEM) reveals face-to-face stacking between MoS2 and 2DPI within the vdWH. This stacking configuration facilitates remarkable charge transfer and noticeable n-type doping effects from monolayer 2DPI to MoS2, as corroborated by Raman spectroscopy, photoluminescence measurements, and field-effect transistor (FET) characterizations. Notably, the 2DPI-MoS2 vdWH exhibits an impressive electron mobility of 50 cm2/V·s, signifying a substantial improvement over pristine MoS2 (8 cm2/V·s). This study unveils the immense potential of integrating 2D polymers to enhance semiconductor device functionality through tailored vdWHs, thereby opening up exciting new avenues for exploring unique interfacial physical phenomena.

Cohort profile: the MUNICH Preterm and Term Clinical study (MUNICH-PreTCl), a neonatal birth cohort with focus on prenatal and postnatal determinants of infant and childhood morbidity.

PURPOSE: The MUNICH Preterm and Term Clinical (MUNICH-PreTCl) birth cohort was established to uncover pathological processes contributing to infant/childhood morbidity and mortality. We collected comprehensive medical information of healthy and sick newborns and their families, together with infant blood samples for proteomic analysis. MUNICH-PreTCl aims to identify mechanism-based biomarkers in infant health and disease to deliver more precise diagnostic and predictive information for disease prevention. We particularly focused on risk factors for pregnancy complications, family history of genetically influenced health conditions such as diabetes and paediatric long-term health-all to be further monitored and correlated with proteomics data in the future. PARTICIPANTS: Newborns and their parents were recruited from the Perinatal Center at the LMU University Hospital, Munich, between February 2017 and June 2019. Infants without congenital anomalies, delivered at 23-41 weeks of gestation, were eligible. FINDINGS: Findings to date concern the clinical data and extensive personal patient information. A total of 662 infants were recruited, 44% were female (36% in preterm, 46% in term). 90% of approached families agreed to participate. Neonates were grouped according to gestational age: extremely preterm (<28 weeks, N=28), very preterm (28 to <32 weeks, N=36), late preterm (32 to <37 weeks, N=97) and term infants (>37+0 weeks, N=501). We collected over 450 data points per child-parent set, (family history, demographics, pregnancy, birth and daily follow-ups throughout hospitalisation) and 841 blood samples longitudinally. The completion rates for medical examinations and blood samples were 100% and 95% for the questionnaire. FUTURE PLANS: The correlation of large clinical datasets with proteomic phenotypes, together with the use of medical registries, will enable future investigations aiming to decipher mechanisms of disorders in a systems biology perspective. TRIAL REGISTRATION NUMBER: DRKS (00024189); Pre-results.