Experimental study of negative pressure wound therapy combined with platelet-rich fibrin for bone-exposed wounds

Aim: To evaluate the efficacy of negative pressure wound therapy (NPWT) combined with platelet-rich fibrin (PRF) in treating bone-exposed wounds and explore its possible mechanism. Materials & methods: A bone-exposed wound was created in a total of 32 healthy Sprague-Dawley rats, which were treated with either control, NPWT group, PRF group or both (N + P group). The bone-exposed area, skin contraction rate and granulation coverage and the level of growth factors in granulation tissue were determined on days 4, 7 and 10. Results: The N + P group showed significantly higher wound closure rate than that achieved with others respectively. Four factors were significantly higher in N + P group than in the other three groups. Conclusion: Combination of NPWT and PRF can repair bone-exposed wounds effectively and accelerate wound healing.

Coronavirus Variants of Concern: An Insight

The new coronavirus, SARS-CoV-2, which causes the disease COVID-19, has had a serious worldwide impact on human health. The virus was virtually unknown at the beginning of 2020. Since then, intense research efforts have resulted in sequencing the coronavirus genome, identifying the structures of its proteins, and creating a wide range of tools to search for effective vaccines and therapies. Also, there’s a chance that the COVID-19 contraction rate could get higher than the COVID-19 vaccination rate. In other words, the virus continues to spread while very little people actually get vaccinated. This only makes the job of scientists even harder. In order to stop the spread of COVID-19, citizens must get vaccinated more frequently than citizens are contracting COVID-19. The coronavirus attacks and kills healthy cells, causing detrimental damage to the respiratory system and immune system. It was then discovered that COVID-19 can be terribly fatal for those with already fragile immune systems and preexisting health conditions. Back in March, when COVID-19 was clearly becoming a critical threat to many countries around the world, the evidence indicated that the virus spreads from person to person through small respiratory droplets produced when people cough or sneeze, or even breathe. Surfaces can serve as an intermediary for the virus when looking for a host. Instead of contracting the virus directly from a person, it is possible to receive the virus from touching an object that an infected person sneezed on. It has been discovered that the virus can last up to three 3 days on a surface. Proceeding to rub one’s eyes, mouth, or nose after such contact is also a mode of transmission.

Anti-diabetic and wound healing potential of Benincasa hispida in streptozotocin-induced diabetic rats

Benincasa hispida (B.hispida) is a potential bioactive herb with a wide range of pharmacological actions. Diabetes wound healing effect of effect of B.hispida is not clear. Hence the study was planned to investigate the antidiabetic and wound healing activities of methanolic and petroleum ether of B.hispida on streptozotocin-induced diabetes mellitus in Wistar rats. Diabetes was induced by a single intra peritoneal injection of Streptozocin (60mg/kg). The antidiabetic activity was studied at 50, 100 and 200 mg/kg body weight (BW) of plant extracts. In this study, STZ intoxicated rats displayed increased blood glucose level, lipid peroxidation and decreased level of antioxidants. Further, lipid profiles such as total cholesterol, triglycerides, LDL and VLDL were significantly increased and HDL was significantly decreased in STZ diabetic rats. Treatment with B.hispida methanolic and petroleum extracts at the dose of 100 and 200mg/kg showed significant antidiabetic activity. Further, in wounded rats, B.hispida significantly increased the wound contraction rate and shorten the period of epithelization. In conclusion, B.hispida showed a significant antidiabetic and wound activities mediated through its antioxidant effect.

Effects and Characterization of Some Topical Ointments Based on Vegetal Extracts on Incision, Excision, and Thermal Wound Models

The present paper aims to formulate and characterize four phytotherapeutic ointments based on Hippophae fructus, Calendulae flos, Bardanae folium, and Millefolii herba, which are included in a novel ointment base. In order to investigate the healing properties of the ointments, in vivo experimental wound models of linear incision, circular excision, and thermal burn were performed on Wistar rats. Topical treatment was performed daily for 21 days. Determination of the wound contraction rate (WCR), the period of reepithelization, and histopathological examination were achieved. Additionally, for the tested ointments, oscillatory and rotational rheological tests were carried out, and for the extracts, HPLC analysis was performed. The results demonstrate that the tested novel ointments are safe for use and the most effective ointment proved to be the one based on Arctium lappa, followed by that of Calendulae flos.

Coenzyme Q10 Efficacy Test for Human Skin Equivalents Using a Pumpless Skin-On-A-Chip System

A human skin equivalent (HSE) composed of the epidermis and dermis is cultured using a pumpless skin-on-a-chip system to supply cultures the desired flow rate using gravity flow without a pump or an external tube connection. Coenzyme Q10 efficacy is tested by adjusting its concentration, as it is known to have anti-aging and antioxidant effects in culture solutions. The relationship between the contraction rate of a full-thickness human skin equivalent and secreted transforming growth factor (TGF) β-1 is analyzed via enzyme-linked immunosorbent assay (ELISA). Following hematoxylin and eosin (H&E) staining, an image of the skin equivalent is analyzed to measure the epidermal layer’s thickness. The cell density and differentiation of the dermis layer are investigated. Gene and protein expression in the dermal and epidermal layers are quantitatively analyzed using quantitative real time polymerase chain reaction (qPCR) and immunohistochemical staining. As the coenzyme Q10 treatment concentration increased, the number of cells per unit area and the thickness of the epidermal layer increased, the expression level of filaggrin increased, and the contraction rate of full-thickness HSE was proportional to the amount of TGF β-1 secreted.

Optimal Bayesian estimation for random dot product graphs

Summary We propose and prove the optimality of a Bayesian approach for estimating the latent positions in random dot product graphs, which we call posterior spectral embedding. Unlike classical spectral-based adjacency, or Laplacian spectral embedding, posterior spectral embedding is a fully likelihood-based graph estimation method that takes advantage of the Bernoulli likelihood information of the observed adjacency matrix. We develop a minimax lower bound for estimating the latent positions, and show that posterior spectral embedding achieves this lower bound in the following two senses: it both results in a minimax-optimal posterior contraction rate and yields a point estimator achieving the minimax risk asymptotically. The convergence results are subsequently applied to clustering in stochastic block models with positive semidefinite block probability matrices, strengthening an existing result concerning the number of misclustered vertices. We also study a spectral-based Gaussian spectral embedding as a natural Bayesian analogue of adjacency spectral embedding, but the resulting posterior contraction rate is suboptimal by an extra logarithmic factor. The practical performance of the proposed methodology is illustrated through extensive synthetic examples and the analysis of Wikipedia graph data.

Doppler Circulation as a Fairly Range-Insensitive Far-Field Tornado Detection and Precursor Parameter

Formulas are obtained for observed circulation around and contraction rate of a Doppler radar grid cell within a surface of constant launch angle. The cell values near unresolved axisymmetric vortices vary greatly with beam-to-flow angle. To obtain reliable standard measures of vortex strength we bilinearly interpolate data to points on circles of specified radii concentric with circulation centers and compute the Doppler circulations around and the areal contraction rates of these circles from the field of mean Doppler velocities. These parameters are proposed for detection of strong tornadoes and mesocyclonic winds. The circulation and mean convergence around the Union City, Oklahoma, tornado of 24 May 1973 are computed. After doubling to compensate for the unobserved wind component, the circulation (1.1 × 105 m2 s−1) agrees with a previous photogrammetric measurement. The mature tornado was embedded in a region, 6 km in diameter, of nearly uniform strong convergence (~5.5 × 10−3 s−1) without a simultaneous mesocyclone. A model of a convergent vortex inputted to a Doppler radar emulator reproduces these results. Moving the model vortex shows that for a WSR-88D with superresolution, the circulation is relatively insensitive to range and azimuth. WSR-88D data of the 31 May 2013 El Reno storm are also analyzed. The tornado formed in a two-celled mesocyclone with strong inflow 5 km away. In the next 8 min the circulation near the axis doubled and the areal contraction rate at 5 km increased by 50%. This signified a large probability of strong tornadoes embedded in powerful storm-scale winds.

Nicotiana tabacum (Tobacco) Promotes Wound Healing in Diabetic Rats

Objective: The health hazards of tobacco smoking and diabetes mellitus constitute major and diverse global burden. The influence of Nicotiana tabacum (tobacco) powder and ethanolic extract on excised wound of diabetic rats was investigated. Methods: The wounds of diabetic adult male wistar rats in groups of six were dressed with tobacco powder (TPD), tobacco ethanolic extract (TED), sofratulle (SD) and normal saline (ND) daily till healed. There were composite control groups namely TPC, TEC, SC and NC. Every three days, the wound areas were measured in order to calculate the mean wound contraction rates. Granulation tissue was biopsied from an animal per group on day 3,6 and 9 for histopathological evaluation and after healing, the scars of the remaining animals were biopsied for histology. Results: On day 3, the tobacco powder diabetic (TPD) group had the highest mean wound contraction rate and even higher than its control group. At day 18, the tobacco extract control group had the least mean wound contraction rate. The mean wound contraction rates of some diabetic groups were significantly higher than those of the respective control on day 3 and 12 (TPD vs TPC; TED vs TEC). The TPD mean wound contraction rates were significantly higher than those of ND on day 3,6,9 and 12. Histology of the granulation tissues of the tobacco diabetic groups was similar to those of the other groups. Sections of the wound scars revealed stratified squamous epithelia with abundant collagen fibres and blood vessels in all the groups. It was also observed that the scars were more fibrous than cellular with dermal appendages observed in some of the groups. Conclusion: Topical application of Nicotiana tabacum (Tobacco) promotes wound healing with scars comparable to those of rats dressed with sofratulle.