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Fulltext Assessment of fracture healing properties of lovastatin loaded nanoparticles: preclinical study in rat model

Zhu P, Huang G, Zhang B, Zhang W, Dang M, Huang Z

Acta Biochim. Pol., 2019 Mar 11;66(1):71-76.
PMID: 30856636 DOI: 10.18388/abp.2018_2719

Bone fracture, being mainly caused by mechanical stress, requires special and quick attention for a rapid healing. The study presented here aims at formulating nanoparticulate system to overcome the solubility issues of lovastatin. The lovastatin nanoparticles were successfully prepared by ionotropic gelation method using chitosan and tri-polyphosphate as polymers. Thus prepared nanoparticles were found to be smooth and spherical with average particle size of 87 nm and encapsulation efficiency of 86.5%. The in-vitro drug release was found to be almost 89.6% in the first 360 minutes. Artificial fracture was produced in female Wistar rats at right leg using fracture apparatus. After administration of lovastatin nanoparticles or saline solution, the respective groups were observed for various parameters. The X-ray imaging showed that lovastatin accelerated bone healing, compared to control. The growth of animals was not hampered by lovastatin by any means. The radiographic examination confirmed a role of lovastatin in increasing bone density. The histological study showed the broken, proliferated and discontinued trabecullae in the control, while at the same time point, the normal, thick, continuous and connected trabecullae were observed in animals administered with lovastatin nanoparticles. The biomechanical studies showed high breaking resilience and minimum bone brittleness in animals injected with lovastatin nanoparticles. Considering these observations we state that lovastatin helps in rapid bone healing after fracture via increasing the bone density.
Fulltext Inhibition of Heterogeneous Nucleation in Water by Hydrogel Coating

Li S, Zhu P, Xue Y, Wang L, Wong TW, Yang X, et al.

Research (Wash D C), 2023;6:0190.
PMID: 37426472 DOI: 10.34133/research.0190

Heterogeneous nucleation plays a critical role in the phase transition of water, which can cause damage in various systems. Here, we report that heterogeneous nucleation can be inhibited by utilizing hydrogel coatings to isolate solid surfaces and water. Hydrogels, which contain over 90% water when fully swelled, exhibit a high degree of similarity to water. Due to this similarity, there is a great energy barrier for heterogeneous nucleation along the water-hydrogel interface. Additionally, hydrogel coatings, which possess polymer networks, exhibit higher fracture energy and more robust adhesion to solid surfaces compared to water. This high fracture and adhesion energy acts as a deterrent for fracture nucleation within the hydrogel or along the hydrogel-solid interface. With a hydrogel layer approximately 100 μm thick, the boiling temperature of water under atmospheric pressure can be raised from 100 to 108 °C. Notably, hydrogel coatings also result in remarkable reductions in cavitation pressure on multiple solid surfaces. We have demonstrated the efficacy of hydrogel coatings in preventing damages resulting from acceleration-induced cavitation. Hydrogel coatings have the potential to alter the energy landscape of heterogeneous nucleation on the water-solid interface, making them an exciting avenue for innovation in heat transfer and fluidic systems.
Accurate wavelet thresholding method for ECG signals

Yu K, Feng L, Chen Y, Wu M, Zhang Y, Zhu P, et al.

Comput Biol Med, 2024 Feb;169:107835.
PMID: 38096762 DOI: 10.1016/j.compbiomed.2023.107835

Current wavelet thresholding methods for cardiogram signals captured by flexible wearable sensors face a challenge in achieving both accurate thresholding and real-time signal denoising. This paper proposes a real-time accurate thresholding method based on signal estimation, specifically the normalized ACF, as an alternative to traditional noise estimation without the need for parameter fine-tuning and extensive data training. This method is experimentally validated using a variety of electrocardiogram (ECG) signals from different databases, each containing specific types of noise such as additive white Gaussian (AWG) noise, baseline wander noise, electrode motion noise, and muscle artifact noise. Although this method only slightly outperforms other methods in removing AWG noise in ECG signals, it far outperforms conventional methods in removing other real noise. This is attributed to the method's ability to accurately distinguish not only AWG noise that is significantly different spectrum of the ECG signal, but also real noise with similar spectra. In contrast, the conventional methods are effective only for AWG noise. In additional, this method improves the denoising visualization of the measured ECG signals and can be used to optimize other parameters of other wavelet methods to enhancing the denoised periodic signals, thereby improving diagnostic accuracy.
Biochar-based solid acid accelerated carbon conversion by increasing the abundance of thermophilic bacteria in the cow manure composting process

Zhu P, Li J, Wen X, Huang Y, Yang H, Wang S, et al.

J Environ Manage, 2022 Feb 07;308:114682.
PMID: 35144065 DOI: 10.1016/j.jenvman.2022.114682

This study investigated the effects of biochar-based solid acids (SAs) on carbon conversion, alpha diversity and bacterial community succession during cow manure composting with the goal of providing a new strategy for rapid carbon conversion during composting. The addition of SA prolonged the thermophilic phase and accelerated the degradation of lignocellulose; in particular, the degradation time of cellulose was shortened by 50% and the humus content was increased by 22.56% compared with the control group (CK). In addition, high-throughput sequencing results showed that SA improved the alpha diversity and the relative abundance of thermophilic bacteria, mainly Actinobacteria, increased by 12.955% compared with CK. A redundancy analysis (RDA) showed that Actinobacteria was positively correlated with the transformation of carbon.
Effects of cryopreservation on gram-positive bacteria contaminants in umbilical cord blood

Boey KPY, Zhu P, Tan H, Abdullah MAB, Tang KF, Li MM, et al.

Transfus Med, 2022 Feb;32(1):82-87.
PMID: 34862686 DOI: 10.1111/tme.12834

OBJECTIVE: To evaluate the effects of cryopreservation in post-thaw umbilical cord blood units for the survivability of Gram-positive bacteria strains.
BACKGROUND: Microbial screening is required for all cord blood units (CBUs). Four gram-positive contaminants were documented to survive cryopreservation poorly and isolation of other contaminants were reported.
METHODS: Forty-eight contaminated CBUs detected with either Staphylococcus epidermidis, Corynebacterium species, Peptostreptococcus or Streptococcus species before cryopreservation were used in this study. CBUs were processed, DMSO-infused and microbial screened before cryopreservation. Post-thaw microbial screening was achieved using 1 and 10 ml inoculants in BACTEC culture bottles. Positive bottles were subjected for microbial identification and results were compared with those from pre-freeze.
RESULTS: A higher rate of microbial contamination was found using the 10 ml inoculant. Screening of 11 CBUs did not detect any contaminants while 30 CBUs screened detected more than one unknown contaminants and majority of contaminants were identified to be gram-negative species.
CONCLUSION: A higher inoculation volume used at post-thaw for microbial screening improves contamination detection but leads to the loss of precious cord blood. Some contaminants did not survive cryopreservation or were not identified due to their low microbial levels. Contrasting contaminants found at post-thaw suggest the improvements made in detection and identification of contaminants over the years.
Fulltext Molecular landscape of immune pressure and escape in aplastic anemia

Pagliuca S, Gurnari C, Hercus C, Hergalant S, Nadarajah N, Wahida A, et al.

Leukemia, 2023 Jan;37(1):202-211.
PMID: 36253429 DOI: 10.1038/s41375-022-01723-w

Idiopathic aplastic anemia (IAA) pathophysiology is dominated by autoreactivity of human leukocyte antigen (HLA)-restricted T-cells against antigens presented by hematopoietic stem and progenitor cells (HSPCs). Expansion of PIGA and HLA class I mutant HSPCs have been linked to immune evasion from T-cell mediated pressures. We hypothesized that in analogy with antitumor immunity, the pathophysiological cascade of immune escape in IAA is initiated by immunoediting pressures and culminates with mechanisms of clonal evolution characterized by hits in immune recognition and response genes. To that end, we studied the genetic and transcriptomic make-up of the antigen presentation complexes in a large cohort of patients with IAA and paroxysmal nocturnal hemoglobinuria (PNH) by using single-cell RNA, high throughput DNA sequencing and single nucleotide polymorphism (SNP)-array platforms. At disease onset, HSPCs displayed activation of selected HLA class I and II-restricted mechanisms, without extensive inhibition of immune checkpoint apparatus. Using a newly implemented bioinformatic framework we found that not only class I but also class II genes were often impaired by acquisition of genetic aberrations. We also demonstrated the presence of novel somatic alterations in immune genes possibly contributing to the evasion from the autoimmune T-cells. In contrast, these hits were absent in myeloid neoplasia. These aberrations were not mutually exclusive with PNH and did not correlate with the accumulation of myeloid-driver hits. Our findings shed light on the mechanisms of immune activation and escape in IAA and define alternative modes of clonal hematopoiesis.
Multi-country evidence that crop diversification promotes ecological intensification of agriculture

Gurr GM, Lu Z, Zheng X, Xu H, Zhu P, Chen G, et al.

Nat Plants, 2016 02 22;2:16014.
PMID: 27249349 DOI: 10.1038/nplants.2016.14

Global food security requires increased crop productivity to meet escalating demand(1-3). Current food production systems are heavily dependent on synthetic inputs that threaten the environment and human well-being(2,4,5). Biodiversity, for instance, is key to the provision of ecosystem services such as pest control(6,7), but is eroded in conventional agricultural systems. Yet the conservation and reinstatement of biodiversity is challenging(5,8,9), and it remains unclear whether the promotion of biodiversity can reduce reliance on inputs without penalizing yields on a regional scale. Here we present results from multi-site field studies replicated in Thailand, China and Vietnam over a period of four years, in which we grew nectar-producing plants around rice fields, and monitored levels of pest infestation, insecticide use and yields. Compiling the data from all sites, we report that this inexpensive intervention significantly reduced populations of two key pests, reduced insecticide applications by 70%, increased grain yields by 5% and delivered an economic advantage of 7.5%. Additional field studies showed that predators and parasitoids of the main rice pests, together with detritivores, were more abundant in the presence of nectar-producing plants. We conclude that a simple diversification approach, in this case the growth of nectar-producing plants, can contribute to the ecological intensification of agricultural systems.