Characterization of Laser-Resistant Port Wine Stain Blood Vessels Using In Vivo Reflectance Confocal Microscopy.

Background and objectivesPort wine stain (PWS) is a congenital vascular malformation of the human skin. Laser is the treatment of choice for PWS. Laser-resistant PWS is one crucial factor accounting for inadequate treatment outcome, which needs to be fully characterized. This study aims to quantitatively characterize the morphology of laser-resistant PWS blood vessels in the upper papillary dermis using in vivo reflectance confocal microscopy (RCM).Study design/materials and methodsA total of 42 PWS subjects receiving laser treatment from August 2016 through July 2018 were enrolled into this study. Thirty-three subjects had facial PWS; nine had extremity PWS. All subject's PWS received multiplex 585/1,064 nm laser treatment. RCM images were taken before and after treatment. The density, diameter, blood flow, and depth of PWS blood vessels were analyzed.ResultsWe found 44.4% PWS on the extremities (four out of nine subjects) were laser-resistant, which was significantly higher (P < 0.001) when compared with those PWS on the face (15.2%, 5 out of 33 subjects). The laser-resistant facial PWS blood vessels had significantly higher blood flow (1.35 ± 0.26 U vs. 0.89 ± 0.22 U, P < 0.001), larger blood vessel diameters (109.60 ± 18.24 µm vs. 84.36 ± 24.04 µm, P = 0.033) and were located deeper in the skin (106.01 ± 13.87 µm vs. 87.82 ± 12.57 µm, P < 0.001) in the skin when compared with laser-responsive PWS on the face. The average PWS blood vessel density (17.01 ± 4.63/mm2 vs. 16.61 ± 4.44/mm2 , P = 0.857) was not correlated to the laser resistance.ConclusionsLaser-resistant PWS blood vessels had significantly higher blood flow, larger diameters, and were located deeper in the skin. RCM can be a valuable tool for a prognostic evaluation on laser-resistant lesions before treatment, thereby providing guidance for tailored laser treatment protocols, which may improve the therapeutic outcome. The limitations for this study include relative small sample size and acquisitions of different blood vessels before and after 2 months of treatment. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc

Computational Discovery and Characterization of New B2O Phases

We present computational discoveries of new structural phases of B2O compound exhibiting novel bonding networks and electronic states at ambient and elevated pressures. Our advanced crystal structure searches in conjunction with density functional theory calculations have identified an orthorhombic phase of B2O that is energetically stable at ambient pressure and contains an intriguing bonding network of icosahedral B12 clusters bridged by oxygen atoms. As pressure increases above 1.9 GPa, a structural transformation takes the orthorhombic B2O into a pseudo- layered trigonal phase. We have performed extensive studies to investigate the evolution of chemical bonds and electronic states associated with the B12 icosahedral unit in the orthorhombic phase and the covalent B-O bonds in the trigonal phase. We also have examined the nature of the charge carriers and their coupling to the lattice vibrations in the newly identified B2O crystals. Interestingly, our results indicate that both B2O phases become superconducting at low temperatures, with transition temperatures of 6.4 K and 5.9 K, respectively, in the ambient and high-pressure phase. The present findings establish new B2O phases and characterize their structural and electronic properties, which offer insights and guidance for exploration toward further fundamental understanding and potential synthesis and application

A Novel Wind Turbine Concept Based on an Electromagnetic Coupler and the Study of Its Fault Ride-through Capability

This paper presents a novel type of variable speed wind turbine with a new drive train different from the variable speed wind turbine commonly used nowadays. In this concept, a synchronous generator is directly coupled with the grid, therefore, the wind turbine transient overload capability and grid voltage support capability can be significantly improved. An electromagnetic coupling speed regulating device (EMCD) is used to connect the gearbox high speed shaft and synchronous generator rotor shaft, transmitting torque to the synchronous generator, while decoupling the gearbox side and the synchronous generator, so the synchronous generator torque oscillations during a grid fault are not transmitted to the gearbox. The EMCD is composed of an electromagnetic coupler and a one quadrant operation converter with reduced capability and low cost. A control strategy for the new wind turbine is proposed and a 2 MW wind turbine model is built to study the wind turbine fault ride-through capability. An integrated simulation environment based on the aeroelastic code HAWC2 and software Matlab/Simulink is used to study its fault ride-through capability and the impact on the structural loads during grid three phase and two phase short circuit faults

Clinical dilemma and systemic treatment strategy of triple-negative breast cancer in the elderly

There is no specific biomarker for triple-negative breast cancer (TNBC), and chemotherapy remains as backbone but with limited efficacy and more side effects. 10%-21% TNBC are elderly patients with high prevalence of concomitant cardio-cerebrovascular and renal complications, which may lead to intolerance of chemotherapy. How to properly treat these elderly TNBC patients becomes a big challenge during daily clinical practice. To date, few clinical trials specifically focus on elderly TNBC patients, thus no enough evidence-based safety and efficacy data are provided to support the proper therapy to this population. There are also challenges and controversies in the diagnosis and treatment. Elderly TNBC patients have special age-related disease characteristics and high non-cancer related mortality. Therefore, it is very important to balance survival benefit and quality of life during the treatment. This paper summarized data of the epidemiology, tumor biological behavior, current diagnosis and treatment status and the huge unmet medical needs of elderly TNBC patients, and explored the benefits of novel antibody-drug conjugate (ADC), to provide certain guidance on systemic treatment strategies for elderly TNBC patients

Hydropower reservoirs on the upper Mekong river modify nutrient bioavailability downstream

Hydropower development is the key strategy in many developing countries for energy supply, climate-change mitigation and economic development. However, it is commonly assumed that river dams retain nutrients and therefore reduce downstream primary productivity and fishery catches, compromising food security and causing trans-boundary disputes. Contrary to expectation, here we found that a cascade of reservoirs along the upper Mekong River increased downstream bioavailability of nitrogen and phosphorus. The dams caused phytoplankton density to increase with hydraulic residence time and stratification of the stagnant reservoirs caused hypoxia at depth. This allowed the release of bioavailable phosphorus from the sediment and an increase in dissolved inorganic nitrogen as well as a shift in nitrogen species from nitrate to ammonium, which were transported downstream by the discharge of water from the base of the dam. Our findings provide a new perspective on the environmental impacts of river dams on nutrient cycling and ecosystem functioning, with potential implications for sustainable development of hydropower worldwide

Evidence of elevation-dependent warming from the Chinese Tian Shan

The phenomenon in which the warming rate of air temperature is amplified with elevation is termed elevation-dependent warming (EDW). It has been clarified that EDW can accelerate the retreat of glaciers and melting of snow, which can have significant impacts on the regional ecological environment. Owing to the lack of high-density ground observations in high mountains, there is widespread controversy regarding the existence of EDW. Current evidence is mainly derived from typical high-mountain regions such as the Swiss Alps, the Colorado Rocky Mountains, the tropical Andes and the Tibetan Plateau–Himalayas. Rare evidence in other mountain ranges has been reported, especially in arid regions. In this study, EDW features (regional warming amplification and altitude warming amplification) in the Chinese Tian Shan (CTM) were detected using a unique high-resolution (1 km, 6-hourly) air temperature dataset (CTMD) from 1979 to 2016. The results showed that there were significant EDW signals at different altitudes on different timescales. The CTM showed significant regional warming amplification in spring, especially in March, and the warming trends were greater than those of continental China with respect to three temperatures (minimum temperature, mean temperature and maximum temperature). The significance values of EDW above different altitude thresholds are distinct for three temperatures in 12 months. The warming rate of the minimum temperature in winter showed a significant elevation dependence (p<0.01), especially above 3000 m. The greatest altitudinal gradient in the warming rate of the maximum temperature was found above 4000 m in April. For the mean temperature, the warming rates in June and August showed prominent altitude warming amplification but with different significance above 4500 m. Within the CTM, the Tolm Mountains, the eastern part of the Borokoonu Mountains, the Bogda Mountains and the Balikun Mountains are representative regions that showed significant altitude warming amplification on different timescales. This new evidence could partly explain the accelerated melting of snow in the CTM, although the mechanisms remain to be explored

Limited Regeneration Potential with Minimal Epicardial Progenitor Conversions in the Neonatal Mouse Heart after Injury

The regeneration capacity of neonatal mouse heart is controversial. In addition, whether epicardial cells provide a progenitor pool for de novo heart regeneration is incompletely defined. Following apical resection of the neonatal mouse heart, we observed limited regeneration potential. Fate-mapping of Tbx18MerCreMer mice revealed that newly formed coronary vessels and a limited number of cardiomyocytes were derived from the T-box transcription factor 18 (Tbx18) lineage. However, further lineage tracing with SM-MHCCreERT2 and Nfactc1Cre mice revealed that the new smooth muscle and endothelial cells are in fact derivatives of pre-existing coronary vessels. Our data show that neonatal mouse heart can regenerate but that its potential is limited. Moreover, although epicardial cells are multipotent during embryogenesis, their contribution to heart repair through "stem" or "progenitor" cell conversion is minimal after birth. These observations suggest that early embryonic heart development and postnatal heart regeneration are distinct biological processes. Multipotency of epicardial cells is significantly decreased after birth

Cardiac Sca-1+ cells are not intrinsic stem cells for myocardial development, renewal and repair

Background: For over a decade, Sca-1+ cells within the mouse heart have been widely recognized as a stem cell population with multipotency that can give rise to cardiomyocytes, endothelial cells and smooth muscle cells in vitro and after cardiac grafting. However, the developmental origin and authentic nature of these cells remain elusive. Methods: Here, we used a series of high-fidelity genetic mouse models to characterize the identity and regenerative potential of cardiac resident Sca-1+ cells. Results: With these novel genetic mouse models, we found that Sca-1 does not label cardiac precursor cells during early embryonic heart formation. Postnatal cardiac resident Sca-1+ cells are in fact a pure endothelial cell population. They retain endothelial properties and exhibit minimal cardiomyogenic potential during development, normal aging and upon ischemic injury. Conclusions: Our study provides definitive insights into the nature of cardiac resident Sca-1+ cells. The observations challenge the current dogma that cardiac resident Sca-1+ cells are intrinsic stem cells for myocardial development, renewal and repair and suggest that the mechanisms of transplanted Sca-1+ cells in heart repair need to be reassessed

The contribution of double-fed wind farms to transient voltage and damping of power grids

Kako bi se povećala mogućnost održavanja prolaznog napona i oscilacija sustava prigušenja, u radu se predstavlja dodatna prolazna upravljačka shema vjetroelektrane. Analiza pokazuje da u uvjetima jakih mreža, oslanjanje na vlastitu reaktivnu snagu turbina na vjetar u svrhu podrške pada prolaznog napona, dovodi do značajnog povećanja struje rotora; u uvjetima slabih mreža, prolazna reaktivna snaga vjetroelektrana ne samo da služi za prigušivanje pada prolaznog napona nego i čini prihvatljivom povećanje uzbudne struje rotora. Uz to, kad se dvostruko napajani indukcioni generatori pomiješaju s konvencionalnim energanama za prijenos snage, moguće je upravljati povećanjem prigušenja sustava dodajući prigušenje preko vjetroelektrana u nastojanju poboljšanja stabilnosti cjelokupnog sustava. U svrhu implementacije ove sheme, proizvodimo eksperimentalni prototip sastavljen od IPC, glavne sabirnice i optičke opreme i provodimo ispitivanje zatvorene petlje na digitalnom simulatoru u realnom vremenu (RTDS). Simulacije pokazuju da u uvjetima slabih mreža implementacija regulacije reaktivne snage vjetreoelektrana može donekle prigušiti pad napona.To improve the ability of transient voltage support and that of damping system oscillation, this paper presents the additional transient control scheme of wind farm. The analysis indicates that under the condition of strong grids, relying on wind turbines’ own reactive power to support the transient voltage drop leads to the significant increase of rotor current; under the condition of weak grids, transient reactive power released by wind farms not only serves to suppress transient voltage drop but also makes acceptable the increase of rotor excitation current. In addition, when double-fed induction generators are mixed with conventional power plants for power transmission, we can control the increase of system damping by adding damping through wind turbines in a bid to improve the stability of the overall system. In order to implement this scheme, we produce the experimental prototype composed of IPC, fieldbus and optical equipment and conduct the closed-loop test on the real-time digital simulator (RTDS). Simulations show that under the condition of weak grids, implementing the reactive power regulation of wind farms can suppress their voltage drop to a certain extent