Kaempferol inhibits IL‑1β‑induced proliferation of rheumatoid arthritis synovial fibroblasts and the production of COX‑2, PGE2 and MMPs

Inflammatory cytokines, matrix metalloproteinases (MMPs) and cyclooxygenase (COX)‑2 released from rheumatoid arthritis synovial fibroblasts (RASFs) are involved in the destruction of both articular bone and cartilage. Kaempferol has been reported to act as an antioxidant and anti‑inflammatory agent by inhibiting nitric oxide synthase and COX enzymes. The aim of the present study was to determine the effects of kaempferol on the interleukin‑1β (IL‑1β)‑induced proliferation of RASFs and the production of MMPs, COX and prostaglandin E2 (PGE2) by RASFs. The proliferation of the RASFs stimulated with IL‑1β and treated with/without kaempferol was evaluated by CCK‑8 assay. The expression of MMPs, TIMP metallopeptidase inhibitor‑1 (TIMP‑1), COXs, PGE2 and that of intracellular MAPK signaling molecules, including p‑ERK, p‑p38, p‑JNK and nuclear factor‑κB (NF‑κB) was examined by immunoblotting or semi‑quantitative reverse transcription‑polymerase chain reaction (RT‑PCR) and ELISA under the conditions described above. Kaempferol inhibited the proliferation of both unstimulated and IL‑1β‑stimulated RASFs, as well as the mRNA and protein expression of MMP‑1, MMP-3, COX‑2 and PGE2 induced by IL‑1β. Kaempferol also inhibited the phosphorylation of ERK‑1/2, p38 and JNK, as well as the activation of NF‑κB induced by IL‑1β. These results indicate that kaempferol inhibits synovial fibroblast proliferation, as well as the production of and MMPs, COX‑2 and PGE2, which is involved in articular inflammation and destruction in rheumatoid arthritis (RA). Our data suggest that kaempferol may be a novel therapeutic agent for the treatment of RA

Regional differences in raindrop size distribution observed from disdrometers in South Korea and their possible causes

In this study, we examine the regional differences in the characteristics of raindrop size distribution (RSD) among three cities (Seoul, Chuncheon, and Jincheon) in South Korea using disdrometer data for the period from 25 July 2018 to 31 July 2021 and investigate possible causes for the differences. Jincheon, the least populated and southernmost city among the three cities, is characterized by the smallest mean rainfall intensity and a relatively high frequency of light rain. These precipitation characteristics are related to the mass-weighted mean diameter D-m that is smallest and the logarithm of generalized intercept parameter log(10)N(w) that is largest in this city. In contrast, Chuncheon, a medium-sized city located in a basin, is characterized by the largest mean rainfall intensity and a relatively high frequency of heavy rain, which is related to the largest D-m and smallest log(10)N(w). Relatively small (large) convective available potential energy, low (high) cloud top, and high (low) cloud base in Jincheon (Chuncheon) can be responsible for the contrasts in RSD characteristics between the two cities. Seoul, the most populated city, is characterized by the intermediate mean rainfall intensity related to the intermediate D-m and log(10)N(w) between those in Jincheon and Chuncheon. Seoul exhibits the most frequent occurrence of extreme rainfall events and relatively large D-m for very heavy rain, which can be associated with the most frequent occurrence of large convective available potential energy.N

A new warm-cloud collection and breakup parameterization scheme for weather and climate models

Microphysical process rates in bulk microphysics schemes have been parameterized in simple forms which may inadequately represent their complicated dependencies on hydrometeor quantities. In this study, we develop a bulk warm rain microphysics scheme that includes physically based parameterizations of collection and breakup. The parameterizations are derived from the stochastic collection and breakup equations by approximating the collection and breakup kernels in elaborate forms and analytically evaluating the integrals in those equations. Although the new scheme performs relatively complicated calculations, it is computationally not too expensive to be used in weather and climate models. We first evaluate the raindrop self-collection and collisional breakup (RSCB) parameterizations developed in this study using a box model. Under the intrinsic limitation of bulk schemes, they generally yield the equilibrium raindrop size distributions closest to those from a bin-based solver. We then evaluate the new scheme through the simulations of shallow cumuli field and a single warm convective cloud. In the simulation of shallow cumuli field, the new scheme quite well reproduces the observed cloud properties. Compared to two other bulk schemes, the new scheme yields somewhat different rainwater mass and raindrop number concentration, which is largely attributable to the differences in autoconversion parameterizations. In the simulation of a single warm convective cloud where RSCB plays a major role, the rate of raindrop number depletion by RSCB and the time of precipitation onset predicted by the new scheme are close to those predicted by a bin scheme used as the reference.N

Processes associated with extremely heavy precipitation in the Meghalaya Plateau region: A case modelling study

© 2022 Royal Meteorological Society.The Meghalaya Plateau (MP) located in northeast India is one of the rainiest regions in the world. On 18–19 August 2015, Mawsynram on the southern slope of MP received 745 mm of precipitation in 24 hr. This study investigates the dynamical, thermodynamical and cloud microphysical processes associated with this event through numerical simulations with fine horizontal resolutions (1 and 1/3 km). The control (CNTL) simulation with 1 km grid spacing successfully reproduces the observed spatial pattern of accumulated precipitation. A simulation without MP (noMP) is carried out to examine the role of MP in this precipitation. From 1500 LST 18 to 0000 LST 19 (P1) when the low-level jet carrying warm and moist air towards MP is relatively weak, the upslope region receives a moderate amount of precipitation which is initiated over this region due to the orographic lifting, while almost no precipitation is received there in the noMP simulation. Warm microphysical processes play dominant roles in the precipitation in P1. From 0000 to 0900 LST 19 (P2) when the low-level jet is enhanced, the CNTL simulation shows very heavy precipitation in the upslope region, much heavier than that in the noMP simulation. Deep convective systems developed upwind of MP move towards MP. These convective systems merge together and strengthen over the upslope region. The accretion process is substantially enhanced by the vigorous updraughts at low levels over the steep slope of MP, resulting in heavy precipitation. The 1/3 km resolution simulation shows much heavier precipitation in the upslope region than the CNTL simulation. The increased horizontal resolution makes the slopes steeper, resulting in further intensification of the updraughts over this region. This increase in simulated precipitation reduces the deviation from the rain-gauge observation, implying the importance of very high horizontal resolutions in simulating extremely heavy precipitation in MP.N

Effects of Lake Baikal on Summertime Precipitation Climatology Over the Lake Surface

Abstract This study investigates the impacts of Lake Baikal, the largest by volume and the deepest freshwater lake in the world, on its nearby precipitation climate. Satellite observations and a reanalysis data set reveal that summertime precipitation amount is smaller over Lake Baikal than around it. A 15‐year regional climate simulation at a cloud‐resolving scale supports the smaller precipitation, and another simulation in which the lake is replaced by forest shows that the lake reduces summertime precipitation over it by 15%. The lake decreases daytime near‐surface air temperature, resulting in more convectively stable atmosphere over the lake. Latent heat flux is reduced along with the weakened convection, and the lower‐level moisture convergence and upper‐level moisture divergence over the lake are weakened

Tall-building effects on pedestrian-level flow and pollutant dispersion: Large-eddy simulations

© 2022 Turkish National Committee for Air Pollution Research and ControlThe urban environmental impact of tall buildings has increasingly become an important topic of investigation, with the rapid pace of tall-building constructions around the world. In this study, the effects of a tall building on pedestrian-level flow and pollutant dispersion are investigated using the parallelized large-eddy simulation model (PALM). Numerical simulations are conducted by changing the tall-building height in the configuration of a tall building surrounded by low-rise cubical buildings. As the tall-building height increases, the time- and area-averaged pedestrian-level wind speed and pollutant concentration increases and decreases, respectively. Both the rates of changes in the average wind speed and pollutant concentration decrease with increasing tall-building height. The trend of the average wind speed is attributable to an increasing tendency of oncoming flows to pass by the sides of the tall building rather than going down as the tall-building height increases. The trend of the average pollutant concentration is associated with that of the average wind speed. Instantaneous flow and pollutant dispersion are also analyzed. In the upstream region of the tall building, bulks of polluted air are repeatedly transported from further upstream regions and enter the canyon right in front of the tall building, temporarily increasing the pedestrian-level pollutant concentration near the windward wall of the tall building. In the downstream region of the tall building, at the pedestrian level, two counter-rotating vortices appear in the canyon just behind the tall building. Each of these vortices repeatedly develops at one of the two leeward corners of the tall building, moves downstream while changing its size, and disappears after reaching the windward wall of the neighboring low-rise building. These coherent vortices considerably affect the spatiotemporal variation of pedestrian-level pollutant concentration in the canyon just behind the tall building.N

Patients with Parkinson Disease in a Traditional Korean Medicine Hospital: A Five-Year Audit

Parkinson disease (PD) patients’ demand for complementary and alternative medicine (CAM) has thus been increasing. We investigated the characteristics of PD patients who visited the Korean Medicine Hospital, the official CAM clinic in Korea. The medical records of PD patients were reviewed retrospectively. The demographic and disease-related characteristics, motivation for visiting, and treatment modalities were collected and analyzed. Medical records from 618 patients were reviewed. Most patients (67.6%) had been already diagnosed with PD at the initial visit. The most frequent complaint was gait disturbance. Previously diagnosed patients visited most frequently for add-on CAM therapies. The most frequently used CAM therapy was acupuncture. The most frequently prescribed herbal medicine was modified Ukgansan. We found the main reason for seeking out CAM was to compensate for the effects of conventional therapies. Further prospective studies will be necessary to collect enough data and evaluate the effectiveness of CAM therapies