P4HA2 promotes proliferation, invasion, and metastasis through regulation of the PI3K/AKT signaling pathway in oral squamous cell carcinoma.

Proline 4-hydroxylase 2 (P4HA2) is known for its hydroxylase activity, primarily involved in hydroxylating collagen precursors and promoting collagen cross-linking under physiological conditions. Although its overexpression influences a wide variety of malignant tumors' occurrence and development, its specific effects and mechanisms in oral squamous cell carcinoma (OSCC) remain unclear. This study focused on investigating the expression patterns, carcinogenic functions, and underlying mechanisms of P4HA2 in OSCC cells. Various databases, including TCGA, TIMER, UALCAN, GEPIA, and K-M plotter, along with paraffin-embedded samples, were used to ascertain P4HA2 expression in cancer and its correlation with clinicopathological features. P4HA2 knockdown and overexpression cell models were developed to assess its oncogenic roles and mechanisms. The results indicated that P4HA2 was overexpressed in OSCC and inversely correlated with patient survival. Knockdown of P4HA2 suppressed invasion, migration, and proliferation of OSCC cells both in vitro and in vivo, whereas overexpression of P4HA2 had the opposite effects. Mechanistically, the phosphorylation levels of the PI3K/AKT pathway were reduced following P4HA2 silencing. The study reveals that P4HA2 acts as a promising biomarker for predicting prognosis in OSCC and significantly affects metastasis, invasion, and proliferation of OSCC cells through the regulation of the PI3K/AKT signaling pathway.

Synthesis and crystal structures of two racemic 2-heteroaryl-3-phenyl-2,3-di-hydro-4H-pyrido[3,2-e][1,3]thia-zin-4-ones.

3-Phenyl-2-(thio-phen-3-yl)-2,3-di-hydro-4H-pyrido[3,2-e][1,3]thia-zin-4-one (C17H12N2OS2, 1) and 2-(1H-indol-3-yl)-3-phenyl-2,3-di-hydro-4H-pyrido[3,2-e][1,3]thia-zin-4-one 0.438-hydrate (C21H15N3OS·0.438H2O, 2) crystallize in space groups P21/n and C2/c, respectively. The asymmetric unit in each case is comprised of two parent mol-ecules, albeit of mixed chirality in the case of 1 and of similar chirality in 2 with the enanti-omers occupying the neighboring asymmetric units. Structure 2 also has water mol-ecules (partial occupancies) that form continuous channels along the b -axis direction. The thia-zine rings in both structures exhibit an envelope conformation. Inter-molecular inter-actions in 1 are defined only by C-H⋯O and C-H⋯N hydrogen bonds between crystallographically independent mol-ecules. In 2, hydrogen bonds of the type N-H⋯O between independent mol-ecules and C-H⋯N(π) type, and π-π stacking inter-actions between the pyridine rings of symmetry-related mol-ecules are observed.

Crystal structure determination and analyses of Hirshfeld surface, crystal voids, inter-molecular inter-action energies and energy frameworks of 1-benzyl-4-(methyl-sulfan-yl)-3a,7a-di-hydro-1H-pyrazolo-[3,4-d]pyrimidine.

The pyrazolo-pyrimidine moiety in the title mol-ecule, C13H12N4S, is planar with the methyl-sulfanyl substituent lying essentially in the same plane. The benzyl group is rotated well out of this plane by 73.64 (6)°, giving the mol-ecule an approximate L shape. In the crystal, C-H⋯π(ring) inter-actions and C-H⋯S hydrogen bonds form tubes extending along the a axis. Furthermore, there are π-π inter-actions between parallel phenyl rings with centroid-to-centroid distances of 3.8418 (12) Å. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (47.0%), H⋯N/N⋯H (17.6%) and H⋯C/C⋯H (17.0%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 76.45 Å3 and 6.39%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the cohesion of the crystal structure is dominated by the dispersion energy contributions.

New insights into membrane fouling in coagulation-ultrafiltration by cake characteristics analysis: A case study with PACl-Al13 and PACl.

Membrane fouling is a bottleneck issue that hindered the further application of ultrafiltration technology. To alleviate membrane fouling, coagulation-ultrafiltration (C-UF) process using polyaluminum chloride (PACl) and PACl-Al13 with high proportion of Al13O4(OH)247+ as coagulants, respectively, were investigated at various pH conditions. Results indicated that an increase in solution pH contributed to larger floc size and looser floc structure for both PACl and PACl-Al13. It was conducive to the formation of more porous cake, as evidenced by mean pore area and pore area distribution of cake, leading to lower reversible fouling. Furthermore, humic acid (HA) removal presented a trend of first increasing and then decreasing with the increase of pH. The optimal HA removal was achieved at pH 6 regardless of coagulant type, suggesting that the slightest irreversible fouling should be occurred at this point. Interestingly, the irreversible fouling with PACl coagulant achieved a minimum value at pH 9, while the minimal irreversible fouling with PACl-Al13 was observed at pH 6. We speculated that the cake formed by PACl could further intercept HA prior to UF process at alkaline pH. Furthermore, compared with PACl, PACl-Al13 had a stronger charge neutralization ability, thus contributing to more compact floc structure and higher HA removal at various pH conditions. By UF fractionation measurement, higher HA removal for PACl-Al13 was due to higher removal of HA with molecular weight less than 50 kDa.

Mechanical loading on cell-free polymer composite scaffold enhances in situ regeneration of fully functional Achilles tendon in a rabbit model.

Traditional tendon engineering using cell-loaded scaffold has limited application potential due to the need of autologous cells. We hypothesize that potent mechanical loading can efficiently induce in situ Achilles tendon regeneration in a rabbit model by using a cell-free porous composite scaffold. In this study, melt-spinning was used to fabricate PGA (polyglycolic acid) and PLA (polylactic acid) filament fibers as well as non-woven PGA fibers. The PLA/PGA (4:2) filament fibers were further braided into a hybrid yarn，which was knitted into a PLA/PGA tubular mesh with potent mechanical property for sustaining natural tendon strain. The results showed that a complete cross-section of Achilles tendon created a model of full mechanical loading on the bridging scaffold, which could efficiently induce in situ tendon regeneration by promoting host cell infiltration, matrix production and tissue remodeling. Histologically, mechanical loading assisted in forming parallel aligned collagen fibers and tenocytes in a fashion similar to those of native tendon. Transmission electron microscope further demonstrated that mechanical strain induced collagen fibril development by increasing fibril diameter and forming bipolar structure, which resulted in enhanced mechanical properties. Interestingly, the synergistic effect between mechanical loading and hyaluronic acid modification was also observed on the induced tenogenic differentiation of infiltrated host fibroblasts. In conclusion, potent mechanical loading is the key inductive microenvironment for in situ tendon regeneration for this polymer-based composite scaffold with proper matrix modification, which may serve as a universal scaffold product for tendon regeneration.

Synthesis, crystal structure and Hirshfeld surface analysis of 1-[3-(2-oxo-3-phenyl-1,2-di-hydro-quinoxalin-1-yl)prop-yl]-3-phenyl-1,2-di-hydro-quinoxalin-2-one.

In the title compound, C31H24N4O2, the di-hydro-quinoxaline units are both essentially planar with the dihedral angle between their mean planes being 64.82 (4)°. The attached phenyl rings differ significantly in their rotational orientations with respect to the di-hydro-quinoxaline planes. In the crystal, one set of C-H⋯O hydrogen bonds form chains along the b-axis direction, which are connected in pairs by a second set of C-H⋯O hydrogen bonds. Two sets of π-stacking inter-actions and C-H⋯π(ring) inter-actions join the double chains into the final three-dimensional structure.

Ethyl 2-[(2-oxo-2H-chromen-6-yl)-oxy]acetate.

Ethyl 2-[(2-oxo-2H-chromen-6-yl)-oxy]acetate, C13H12O5, a member of the pharmacologically important class of coumarins, crystallizes in the monoclinic C2/c space group in the form of sheets, within which mol-ecules are related by inversion centers and 21 axes. Multiple C-H⋯O weak hydrogen-bonding inter-actions reinforce this pattern. The planes of these sheets are oriented in the approximate direction of the ac face diagonal. Inter-sheet inter-actions are a combination of coumarin system π-π stacking and additional C-H⋯O weak hydrogen bonds between ethyl acet-oxy groups.

Crystal structure, Hirshfeld surface analysis, calculations of inter-molecular inter-action energies and energy frameworks and the DFT-optimized mol-ecular structure of 1-[(1-butyl-1H-1,2,3-triazol-4-yl)meth-yl]-3-(prop-1-en-2-yl)-1H-benzimidazol-2-one.

The benzimidazole entity of the title mol-ecule, C17H21N5O, is almost planar (r.m.s. deviation = 0.0262 Å). In the crystal, bifurcated C-H⋯O hydrogen bonds link individual mol-ecules into layers extending parallel to the ac plane. Two weak C-H⋯π(ring) inter-actions may also be effective in the stabilization of the crystal structure. Hirshfeld surface analysis of the crystal structure reveals that the most important contributions for the crystal packing are from H⋯H (57.9%), H⋯C/C⋯H (18.1%) and H⋯O/O⋯H (14.9%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the most dominant forces in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization of the title compound is dominated via dispersion energy contributions. The mol-ecular structure optimized by density functional theory (DFT) at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state.

2-(10-Bromo-anthracen-9-yl)-N-phenyl-aniline.

In the title compound, C26H18BrN, the central benzene ring makes dihedral angles with its adjacent anthracene ring system and pendant benzene ring of 87.49 (13) and 62.01 (17)°, respectively. The N-H moiety is sterically blocked from forming a hydrogen bond, but weak C-H⋯π inter-actions occur in the extended structure.

Ginger extract loaded Fe2O3/MgO-doped hydroxyapatite: Evaluation of biological properties for bone-tissue engineering.

Since antiquity, the medicinal properties of naturally sourced biomolecules such as ginger (Zingiber officinale) extract are documented in the traditional Indian and Chinese medical systems. However, limited work is performed to assess the potential of ginger extracts for bone-tissue engineering. Our work demonstrates the direct incorporation of ginger extract on iron oxide-magnesium oxide (Fe2O3 and MgO) co-doped hydroxyapatite (HA) for enhancement in the biological properties. The addition of Fe2O3 and MgO co-doping system and ginger extract with HA increases the osteoblast viability up to ~ 1.4 times at day 11. The presence of ginger extract leads to up to ~ 9 times MG-63 cell viability reduction. The co-doping does not adversely affect the release of ginger extract from the graft surface in the biological medium at pH 7.4 for up to 28 days. Assessment of antibacterial efficacy according to the modified ISO 22196: 2011 standard method indicates that the combined effects of Fe2O3, MgO, and ginger extract lead to ~ 82 % more bacterial cell reduction, compared to the control HA against S. aureus. These ginger extract-loaded artificial bone grafts with enhanced biological properties may be utilized as a localized site-specific delivery vehicle for various bone tissue engineering applications.

Construction of ROS-Responsive Hyaluronic Acid Modified Paclitaxel and Diosgenin Liposomes and Study on Synergistic Enhancement of Anti-Ovarian Cancer Efficacy.

Purpose: Ovarian cancer is a fatal gynecologic malignancy with a high rate of abdominal metastasis. Chemotherapy still has a poor clinical prognosis for ovarian cancer patients, with cell proliferation and angiogenesis leading to invasion, migration, and recurrence. To overcome these obstacles, we constructed a novel HA-modified paclitaxel and diosgenin liposome (PEG-TK-HA-PDLPs) using two novel functional materials, DSPE-PEG2000-HA and DSPE-PEG2000-TK-PEG5000, to specifically deliver the drugs to the tumor site in order to reduce OC cell proliferation and anti-angiogenic generation, thereby inhibiting invasion and migration. Methods and Results: PEG-TK-HA-PDLPs were prepared by film dispersion, with ideal physicochemical properties and exhibits active targeting for enhanced cellular uptake. The ZIP synergy score for PTX and Dios was calculated using the online SynergyFinder software to be 3.15, indicating synergy. In vitro results showed that PEG-TK-HA-PDLPs were highly cytotoxic to ID8 cells, induced ID8 cell apoptosis, and inhibited ID8 cell migration and invasion. In vivo studies showed that PEG-TK-HA-PDLPs could prolong the circulation time in the blood, accumulate significantly in the tumor site, and effectively fight against angiogenesis with significant anti-tumor effects. Conclusion: The production of PEG-TK-HA-PDLPs is an effective strategy for the treatment of OC.

Nonsurgical Rhinoplasty: An Updated Systematic Review of Technique, Outcomes, Complications, and Its Treatments.

BACKGROUND: For patients looking for temporary results or who do not want surgery, nonsurgical rhinoplasty using filler injections has become increasingly popular. Filler materials and surgical techniques have improved in recent years, but serious complications remain. Therefore, the aim of this systematic review is to summarize the common types of fillers and injection techniques, complications, and treatment to help clinicians perform in a safer and more effective way. METHODS: A systematic review was performed using keywords and Medical Subject Headings search terms. PubMed, Embase, and the Cochrane Library were searched using the appropriate search terms. Data collected from each study included injection materials, location, technique, patient satisfaction and complications, and treatment. RESULTS: From the 1812 studies identified, 30 were included in the systematic review. A total of 9657 patients underwent nonsurgical rhinoplasty, most commonly with hyaluronic acid (HA) (96.76%), followed by calcium hydroxyapatite (CaHA) (1.22%). Overall satisfaction was 99.08%. The overall incidence of complications was 39.11%, with the highest incidence of erythema and swelling (27.95%). Most of the complications are mild, but there are still 0.27% of the patients who have undergone severe complication-an arterial occlusion. CONCLUSIONS: Nonsurgical rhinoplasty is an effective and relatively safe option for improving the profile of the nose, with a short operative time and high patient satisfaction. Most of the complications were mild, but still serious vascular complications such as blindness, skin necrosis, and stroke were as high as 0.27%. A thorough understanding of the anatomy of the nasal vessels and a precise surgical technique is an important basis for prevention. A BULLET POINT LIST: (1) We summarize the common types of fillers and injection techniques, complications, and treatment of complications to guide physicians to perform nonsurgical rhinoplasty in a safer and more effective manner. (2) Out of 1812 studies through the search strategy, 30 articles were included in the systematic review. A total of 9657 patients underwent nonsurgical rhinoplasty. (3) Nonsurgical rhinoplasty is an effective and relatively safe option to improve the profile of the nose, with a short surgical time and high patient satisfaction. (4) Most of the complications were mild, but some severe complications due to the vascular factors such as blindness, skin necrosis, and cerebral infarction need to be vigilant. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

P4HA2 promotes tumor progression and is transcriptionally regulated by SP1 in colorectal cancer.

P4HA2 has been implicated in various malignant tumors; however, its expression and functional role in colorectal cancer (CRC) remain poorly elucidated. This study aims to investigate the involvement of P4HA2 in CRC metastasis and progression, uncovering the underlying mechanisms. In colorectal cancer (CRC), P4HA2 exhibited overexpression, and elevated levels of P4HA2 expression were associated with an unfavorable prognosis. Functional assays demonstrated P4HA2's regulation of cell proliferation, and epithelial-mesenchymal transition (EMT) both in vitro and in vivo. Additionally, the AGO1 expression was correlated with P4HA2, and depletion of AGO1 reversed the proliferation and EMT function induced by P4HA2. Chromatin immunoprecipitation (ChIP) and luciferase assays suggested that the transcription factor SP1 binds to the promoter sequence of P4HA2, activating its expression in CRC. This study unveiled SP1 as a transcriptional regulator of P4HA2 in CRC and AGO1 is a probable target of P4HA2. In conclusion, P4HA2 emerges as a potential prognostic biomarker and promising therapeutic target in colorectal cancer.

R229I substitution from oseltamivir induction in HA1 region significantly increased the fitness of a H7N9 virus bearing NA 292K.

The proportion of human isolates with reduced neuraminidase inhibitors (NAIs) susceptibility in highly pathogenic avian influenza (HPAI) H7N9 virus was as high as 13%. These drug-resistant strains showed good replication capacity without serious loss of fitness. At the presence of oseltamivir, R229I substitution were found in HA1 region of the HPAI H7N9 virus before NA R292 K appeared. HPAI H7N9 or H7N9/PR8 recombinant viruses were developed to study whether HA R229I could increase the fitness of the H7N9 virus bearing NA 292 K. Replication efficiency was assessed in MDCK or A549 cells. Neuraminidase enzyme activity and receptor-binding ability were analyzed. The pathogenicity in C57 mice was evaluated. Antigenicity analysis was conducted through a two-way HI test, in which the antiserum was obtained from immunized ferrets. Transcriptomic analysis of MDCK infected with HPAI H7N9 24hpi was done. It turned out that HA R229I substitution from oseltamivir induction in HA1 region increased 1)replication ability in MDCK(P < 0.05) and A549(P < 0.05), 2)neuraminidase enzyme activity, 3)binding ability to both α2,3 and α2,6 receptor, 4)pathogenicity to mice(more weight loss; shorter mean survival day; viral titer in respiratory tract, P < 0.05; Pathological changes in pneumonia), 5) transcriptome response of MDCK, of the H7N9 virus bearing NA 292 K. Besides, HA R229I substitution changed the antigenicity of H7N9/PR8 virus (＞4-fold difference of HI titer). It indicated that through the fine-tuning of the HA-NA balance, R229I increased the fitness and change the antigenicity of a H7N9 virus bearing NA 292 K. Public health attention of this mechanism needs to be drawn.

Legal analysis of South Korean cosmetic filler litigations for safer medical practices.

Cosmetic filler injections have gained popularity in recent years, but the rise in complications has led to an increase in legal disputes. This study analyzes civil court rulings related to cosmetic filler injection lawsuits in South Korea from 2007 to 2023. A retrospective case analysis was performed using a systematic database search, and a mixed-methods approach was employed for data analysis. The study examined 27 cases, revealing a high rate of liability findings against medical practitioners. Skin necrosis and blindness were the most common complications, and intravascular filler injection was recognized as negligence. Violation of informed consent was found in most cases, with mean compensation awards of ￦193,019,107 KRW ($142,831 USD) for first instance cases and ￦81,845,052 KRW ($60,564 USD) for second instance cases. The findings emphasize the importance of practitioner awareness, adherence to precautionary measures, and proactive prevention and management of complications. Collaboration among stakeholders is crucial for developing strategies that prioritize patient safety and minimize legal disputes in the aesthetic medicine industry. This study provides valuable insights for enhancing medical practices and safeguarding patient well-being in the field of cosmetic filler injections.

Multi-location evaluation of field pea in Indian climates: eco-phenological dynamics, crop-environment relationships, and identification of mega-environments.

Characterization of crop-growing environments in relation to crop's genotypic performance is crucial to harness positive genotype-by-environment interactions (GEI) in systematic breeding programs. Given that, the study aimed to delineate the impact of diverse environments on crop phenology and yield traits of dwarf-statured field pea, pinpointing location(s) favoring higher yield and distinctiveness within breeding lines. We tested twelve field pea breeding lines across twenty locations in India, covering Central Zone (CZ), North Western Plain Zone (NWPZ), North Eastern Plain Zone (NEPZ), and Northern Hill Zone (NHZ). Across these locations, maximum and minimum temperatures during flowering (TMAXF, TMINF) and reproductive period (TMAXRP, TMINRP) ranged 18.9-28.3, 3.3-18.0, 15.0-30.8, and 7.9-22.1oC, respectively. Meanwhile, notable variations in phenological and agronomic traits (coefficient of variation) were observed: flowering (31%), days to maturity (21%), reproductive period (18%), grain yield (48%), and 100-seed weight (18%). Combined ANOVA demonstrated an oversized impact of environment (81%) on yield, while genotype and GEI effects were 2% and 14%, respectively. The variables TMINF, TMINRP, and cumulative growing degree-day showed positive correlations with yield, while extended vegetative and maturity durations negatively influenced yield (p < 0.05). Additionally, linear mixed-models and PCA results explained that instability in crop phenology had significant influence on field pea yield. Seed weight was markedly varied within the locations (9.9-20.8 g) and both higher and lower seed weights were associated with lower yields (Optimal = 17.1 g). HA-GGE biplot-based on environment focus-scaling demonstrated three mega-environments and specific locations viz. Kota (CZ), SK Nagar (CZ), Raipur (CZ), Sehore (CZ), and Pantnagar (NWPZ) as the ideal testing-environments with high efficiency in selecting new genotypes with wider adaptability. The study findings highlight distinct impact of environments on crop phenology and agronomic traits of field pea (dwarf-type), hold substantial value in designing efficient field pea (dwarf-type) breeding program at mega-environment scale.

The recombinant vaccine of Lactobacillus plantarum elicits immune protection against H1N1 and H9N2 influenza virus infection.

Influenza A virus (IAV) causes annual epidemics and occasional pandemics, resulting in significant economic losses and numerous fatalities. Current vaccines, typically administered through injection, provide limited protection due to the frequent antigenic shift and drift of IAV strains. Therefore, the development of alternative broad-spectrum vaccine strategies is imperative. Lactic acid bacteria (LAB) represent promising candidates for vaccine engineering due to their low cost, high safety profile, and suitability for oral administration. In this study, we identified a strain of Lactobacillus plantarum (Lp) that is resistant to acid and bile salts and capable of colonizing the intestines of mice. Subsequently, we employed the RecE/T gene editing system to integrate headless hemagglutinins (mini-HA) into the genome of Lp, generating Lp-mini-HA-SP. Remarkably, immunization with Lp-mini-HA-SP elicited serum IgG antibody responses and conferred immune protection against H9N2 and H1N1 influenza virus challenges. Collectively, our findings offer a novel approach for the development of orally administered IAV vaccines and hold significant potential for future drug development endeavors.

CD52/FLAG and CD52/HA Fusion Proteins as Novel Magnetic Cell Selection Markers.

At present, the magnetic selection of genetically modified cells is mainly performed with surface markers naturally expressed by cells such as CD4, LNGFR (low affinity nerve growth factor receptor), and MHC class I molecule H-2Kk. The disadvantage of such markers is the possibility of their undesired and poorly predictable expression by unmodified cells before or after cell manipulation, which makes it essential to develop new surface markers that would not have such a drawback. Earlier, modified CD52 surface protein variants with embedded HA and FLAG epitope tags (CD52/FLAG and CD52/HA) were developed by the group of Dr. Mazurov for the fluorescent cell sorting of CRISPR-modified cells. In the current study, we tested whether these markers can be used for the magnetic selection of transduced cells. For this purpose, appropriate constructs were created in MigR1-based bicistronic retroviral vectors containing EGFP and DsRedExpress2 as fluorescent reporters. Cytometric analysis of the transduced NIH 3T3 cell populations after magnetic selection evaluated the efficiency of isolation and purity of the obtained populations, as well as the change in the median fluorescence intensity (MFI). The results of this study demonstrate that the surface markers CD52/FLAG and CD52/HA can be effectively used for magnetic cell selection, and their efficiencies are comparable to that of the commonly used LNGFR marker. At the same time, the significant advantage of these markers is the absence of HA and FLAG epitope sequences in cellular proteins, which rules out the spurious co-isolation of negative cells.

Natural variation in neuraminidase activity influences the evolutionary potential of the seasonal H1N1 lineage hemagglutinin.

The antigenic evolution of the influenza A virus hemagglutinin (HA) gene poses a major challenge for the development of vaccines capable of eliciting long-term protection. Prior efforts to understand the mechanisms that govern viral antigenic evolution mainly focus on HA in isolation, ignoring the fact that HA must act in concert with the viral neuraminidase (NA) during replication and spread. Numerous studies have demonstrated that the degree to which the receptor-binding avidity of HA and receptor-cleaving activity of NA are balanced with each other influences overall viral fitness. We recently showed that changes in NA activity can significantly alter the mutational fitness landscape of HA in the context of a lab-adapted virus strain. Here, we test whether natural variation in relative NA activity can influence the evolutionary potential of HA in the context of the seasonal H1N1 lineage (pdmH1N1) that has circulated in humans since the 2009 pandemic. We observed substantial variation in the relative activities of NA proteins encoded by a panel of H1N1 vaccine strains isolated between 2009 and 2019. We comprehensively assessed the effect of NA background on the HA mutational fitness landscape in the circulating pdmH1N1 lineage using deep mutational scanning and observed pronounced epistasis between NA and residues in or near the receptor-binding site of HA. To determine whether NA variation could influence the antigenic evolution of HA, we performed neutralizing antibody selection experiments using a panel of monoclonal antibodies targeting different HA epitopes. We found that the specific antibody escape profiles of HA were highly contingent upon NA background. Overall, our results indicate that natural variation in NA activity plays a significant role in governing the evolutionary potential of HA in the currently circulating pdmH1N1 lineage.

Influence of natural organic matter on the aggregation dynamics of biochar colloids derived from various feedstocks.

Abundant biochar colloids (BCs) produced from a wide range of feedstocks, resulting from forest fires, agricultural production, and environmental restoration, exhibit varying aggregation behaviors influenced by feedstock type and natural organic matter. However, the impact of natural organic matter on the colloidal stability of BCs derived from different feedstocks remains poorly understood. In this study, six selected biochars were derived from various feedstocks as follows: sewage sludge (SS), rice husk (RH), oil seed rape straw pellets (OSR), wheat straw pellets (WS), miscanthus straw pellets (MS) and softwood pellets (SW). The colloidal stability of BCs, with the exogenous addition of organic matter, was further determined. The order of critical coagulation concentrations (CCCs) of BCs with the presence of humic acid (HA) was as follows: RH (989.48 mM) < MS (1084.69 mM) < SS (1149.76 mM) < WS (1338.99 mM) < OSR (2402.98 mM) < SW (3151.32 mM). This order was significantly positively correlated with the specific surface area and negatively correlated with the ash content of the bulk biochar. Compared to HA, bovine serum albumin (BSA) more effectively inhibited the aggregation behavior of BCs due to steric hindrance. The initial aggregation rate constant (k) of BCs at 3000 mM NaCl was as follows: MS (0.238 nm/s) > OSR (0.142 nm/s) > WS (0.128 nm/s) > SS (0.126 nm/s) > RH (0.118 nm/s) > SW (0.112 nm/s). The stabilizing effects of BSA on biochar colloids were independent of the physicochemical properties of bulk biochar. In the presence of BSA, a thin layer of protein corona significantly enhanced the stability of biochar colloids, particularly the BCs derived from MS. Our results underscore the importance of considering feedstock resources and natural organic matter type when assessing the aggregation and potential risks of BCs in aquatic systems.