Microstructure-dependent particulate filtration using multifunctional metallic nanowire foams.

The COVID-19 pandemic has shown the urgent need for the development of efficient, durable, reusable and recyclable filtration media for the deep-submicron size range. Here we demonstrate a multifunctional filtration platform using porous metallic nanowire foams that are efficient, robust, antimicrobial, and reusable, with the potential to further guard against multiple hazards. We have investigated the foam microstructures, detailing how the growth parameters influence the overall surface area and characteristic feature size, as well as the effects of the microstructures on the filtration performance. Nanogranules deposited on the nanowires during electrodeposition are found to greatly increase the surface area, up to 20 m2 g-1. Surprisingly, in the high surface area regime, the overall surface area gained from the nanogranules has little correlation with the improvement in capture efficiency. However, nanowire density and diameter play a significant role in the capture efficiency of PM0.3 particles, as do the surface roughness of the nanowire fibers and their characteristic feature sizes. Antimicrobial tests on the Cu foams show a >99.9995% inactivation efficiency after contacting the foams for 30 seconds. These results demonstrate promising directions to achieve a highly efficient multifunctional filtration platform with optimized microstructures.

Single-Phase L10-Ordered High Entropy Thin Films with High Magnetic Anisotropy.

The vast high entropy alloy (HEA) composition space is promising for discovery of new material phases with unique properties. This study explores the potential to achieve rare-earth-free high magnetic anisotropy materials in single-phase HEA thin films. Thin films of FeCoNiMnCu sputtered on thermally oxidized Si/SiO2 substrates at room temperature are magnetically soft, with a coercivity on the order of 10 Oe. After post-deposition rapid thermal annealing (RTA), the films exhibit a single face-centered-cubic phase, with an almost 40-fold increase in coercivity. Inclusion of 50 at.% Pt in the film leads to ordering of a single L10 high entropy intermetallic phase after RTA, along with high magnetic anisotropy and 3 orders of magnitude coercivity increase. These results demonstrate a promising HEA approach to achieve high magnetic anisotropy materials using RTA.

Predicting Survival Using Whole-Liver MRI Radiomics in Patients with Hepatocellular Carcinoma After TACE Refractoriness.

PURPOSE: To develop a model based on whole-liver radiomics features of pre-treatment enhanced MRI for predicting the prognosis of hepatocellular carcinoma (HCC) patients undergoing continued transarterial chemoembolization (TACE) after TACE-resistance. MATERIALS AND METHODS: Data from 111 TACE-resistant HCC patients between January 2014 and March 2018 were retrospectively collected. At a ratio of 7:3, patients were randomly assigned to developing and validation cohorts. The whole-liver were manually segmented, and the radiomics signature was extracted. The tumor and liver radiomics score (TLrad-score) was calculated. Models were trained by machine learning algorithms and their predictive efficacies were compared. RESULTS: Tumor stage, tumor burden, body mass index, alpha-fetoprotein, and vascular invasion were revealed as independent risk factors for survival. The model trained by Random Forest algorithms based on tumor burden, whole-liver radiomics signature, and clinical features had the highest predictive efficacy, with c-index values of 0.85 and 0.80 and areas under the ROC curve of 0.96 and 0.83 in the developing cohort and validation cohort, respectively. In the high-rad-score group (TLrad-score > - 0.34), the median overall survival (mOS) was significantly shorter than in the low-rad-score group (17 m vs. 37 m, p < 0.001). A shorter mOS was observed in patients with high tumor burden compared to those with low tumor burden (14 m vs. 29 m, p = 0.007). CONCLUSION: The combined radiomics model from whole-liver signatures may effectively predict survival for HCC patients continuing TACE after TACE refractoriness. The TLrad-score and tumor burden are potential prognostic markers for TACE therapy following TACE-resistance.

Specific convulsions and brain damage in children hospitalized for Omicron BA.5 infection: an observational study using two cohorts.

BACKGROUND: SARS-CoV-2 continues to mutate over time, and reports on children infected with Omicron BA.5 are limited. We aimed to analyze the specific symptoms of Omicron-infected children and to improve patient care. METHODS: We selected 315 consecutively hospitalized children with Omicron BA.5 and 16,744 non-Omicron-infected febrile children visiting the fever clinic at our hospital between December 8 and 30, 2022. Specific convulsions and body temperatures were compared between the two cohorts. We analyzed potential associations between convulsions and vaccination, and additionally evaluated the brain damage among severe Omicron-infected children. RESULTS: Convulsion rates (97.5% vs. 4.3%, P < 0.001) and frequencies (median: 2.0 vs. 1.6, P < 0.001) significantly differed between Omicron-infected and non-Omicron-infected febrile children. The body temperatures of Omicron-infected children were significantly higher during convulsions than when they were not convulsing and those of non-Omicron-infected febrile children during convulsions (median: 39.5 vs. 38.2 and 38.6 °C, both P < 0.001). In the three Omicron-subgroups, the temperature during convulsions was proportional to the percentage of patients and significantly differed ( P < 0.001), while not in the three non-Omicron-subgroups ( P = 0.244). The convulsion frequency was lower in the 55 vaccinated children compared to the 260 non-vaccinated children (average: 1.8 vs. 2.1, P < 0.001). The vaccination dose and convulsion frequency in Omicron-infected children were significantly correlated ( P < 0.001). Fifteen of the 112 severe Omicron cases had brain damage. CONCLUSIONS: Omicron-infected children experience higher body temperatures and frequencies during convulsions than those of non-Omicron-infected febrile children. We additionally found evidence of brain damage caused by infection with omicron BA.5. Vaccination and prompt fever reduction may relieve symptoms.

A Novel Rat Model to Simulate the Benign Esophageal Stricture Induced by Endoscopic Submucosal Dissection.

Objective: This study aimed to establish a rat model that simulates benign esophageal strictures induced by endoscopic submucosal dissection (ESD). Materials and Methods: Sixteen male Sprague-Dawley rats were randomly divided into mucosal resection (n = 8) and sham-operated groups (n = 8). The rats in the mucosal resection group underwent a 5-mm three-fourths mucosal resection by way of a 3-mm incision in the distal esophagus under direct visualization via laparotomy. Rats in the sham-operated group underwent a 3-mm incision of the muscularis propria layer in the distal esophagus via laparotomy without mucosal resection. Dysphagia score, weight gain, mucosal constriction rate, and histology were evaluated 2 weeks after surgery. Results: Technical success was achieved in all the animals. One rat in the mucosal resection group died of infection, and no other complications were observed. Weight gain (P < 0.001) and luminal diameter derived from the esophagograms (P < 0.001) were significantly lower in the mucosal resection group than those in the sham-operated group. Dysphagia score (P < 0.001) and mucosal constriction rate (P < 0.001) were significantly higher in the mucosal resection group than those in the sham-operated group. The inflammation grade (P = 0.002), damage to the muscularis propria (P < 0.001), number of nascent microvessels (P = 0.006), and degree of α-SMA positive deposition (P = 0.006) were significantly higher in the mucosal resection group. Conclusion: A rat model of benign esophageal stricture induced by ESD was successfully and safely established by mucosal resection.

RAD-sequencing improves the genetic characterization of a threatened tree peony (Paeonia ludlowii) endemic to China: Implications for conservation.

Compared with traditional genetic markers, genomic approaches have proved valuable to the conservation of endangered species. Paeonia ludlowii having rarely and pure yellow flowers, is one of the world's most famous tree peonies. However, only several wild populations remain in the Yarlung Zangbo Valley (Nyingchi and Shannan regions, Xizang) in China due to increasing anthropogenic impact on the natural habitats. We used genome-wide single nucleotide polymorphisms to elucidate the spatial pattern of genetic variation, population structure and demographic history of P. ludlowii from the fragmented region comprising the entire range of this species, aiming to provide a basis for conserving the genetic resources of this species. Unlike genetic uniformity among populations revealed in previous studies, we found low but varied levels of intra-population genetic diversity, in which lower genetic diversity was detected in the population in Shannan region compared to those in Nyingzhi region. These spatial patterns may be likely associated with different population sizes caused by micro-environment differences in these two regions. Additionally, low genetic differentiation among populations (Fst = 0.0037) were detected at the species level. This line of evidence, combined with the result of significant genetic differentiation between the two closest populations and lack of isolation by distance, suggested that shared ancestry among now remnant populations rather than contemporary genetic connectivity resulted in subtle population structure. Demographic inference suggested that P. ludlowii probably experienced a temporal history of sharp population decline during the period of Last Glacial Maximum, and a subsequent bottleneck event resulting from prehistoric human activities on the Qinghai-Tibet Plateau. All these events, together with current habitat fragment and excavation might contribute to the endangered status of P. ludlowii. Our study improved the genetic characterization of the endangered tree peony (P. ludlowii) in China, and these genetic inferences should be considered when making different in situ and ex situ conservation actions for P. ludlowii in this evolutionary hotspot region.

Quantized resistance revealed at the criticality of the quantum anomalous Hall phase transitions.

In multilayered magnetic topological insulator structures, magnetization reversal processes can drive topological phase transitions between quantum anomalous Hall, axion insulator, and normal insulator states. Here we report an examination of the critical behavior of two such transitions: the quantum anomalous Hall to normal insulator (QAH-NI), and quantum anomalous Hall to axion insulator (QAH-AXI) transitions. By introducing a new analysis protocol wherein temperature dependent variations in the magnetic coercivity are accounted for, the critical behavior of the QAH-NI and QAH-AXI transitions are evaluated over a wide range of temperature and magnetic field. Despite the uniqueness of these different transitions, quantized longitudinal resistance and Hall conductance are observed at criticality in both cases. Furthermore, critical exponents were extracted for QAH-AXI transitions occurring at magnetization reversals of two different magnetic layers. The observation of consistent critical exponents and resistances in each case, independent of the magnetic layer details, demonstrates critical behaviors in quantum anomalous Hall transitions to be of electronic rather than magnetic origin. Our finding offers a new avenue for studies of phase transition and criticality in QAH insulators.

Strain-tunable Berry curvature in quasi-two-dimensional chromium telluride.

Magnetic transition metal chalcogenides form an emerging platform for exploring spin-orbit driven Berry phase phenomena owing to the nontrivial interplay between topology and magnetism. Here we show that the anomalous Hall effect in pristine Cr2Te3 thin films manifests a unique temperature-dependent sign reversal at nonzero magnetization, resulting from the momentum-space Berry curvature as established by first-principles simulations. The sign change is strain tunable, enabled by the sharp and well-defined substrate/film interface in the quasi-two-dimensional Cr2Te3 epitaxial films, revealed by scanning transmission electron microscopy and depth-sensitive polarized neutron reflectometry. This Berry phase effect further introduces hump-shaped Hall peaks in pristine Cr2Te3 near the coercive field during the magnetization switching process, owing to the presence of strain-modulated magnetic layers/domains. The versatile interface tunability of Berry curvature in Cr2Te3 thin films offers new opportunities for topological electronics.

Characteristics of plastid genomes in the genus Ceratostigma inhabiting arid habitats in China and their phylogenomic implications.

BACKGROUND: Ceratostigma, a genus in the Plumbaginaceae, is an ecologically dominant group of shrubs, subshrub and herb mainly distributed in Qinghai-Tibet Plateau and North China. Ceratostigma has been the focal group in several studies, owing to their importance in economic and ecological value and unique breeding styles. Despite this, the genome information is limited and interspecific relationships within the genus Cerotastigma remains unexplored. Here we sequenced, assembled and characterized the 14 plastomes of five species, and conducted phylogenetic analyses of Cerotastigma using plastomes and nuclear ribosomal DNA (nrDNA) data. RESULTS: Fourteen Cerotastigma plastomes possess typical quadripartite structures with lengths from 164,076 to 168,355 bp that consist of a large single copy, a small single copy and a pair of inverted repeats, and contain 127-128 genes, including 82-83 protein coding genes, 37 transfer RNAs and eight ribosomal RNAs. All plastomes are highly conservative and similar in gene order, simple sequence repeats (SSRs), long repeat repeats and codon usage patterns, but some structural variations in the border of single copy and inverted repeats. Mutation hotspots in coding (Pi values > 0.01: matK, ycf3, rps11, rps3, rpl22 and ndhF) and non-coding regions (Pi values > 0.02: trnH-psbA, rps16-trnQ, ndhF-rpl32 and rpl32-trnL) were identified among plastid genomes that could be served as potential molecular markers for species delimitation and genetic variation studies in Cerotastigma. Gene selective pressure analysis showed that most protein-coding genes have been under purifying selection except two genes. Phylogenetic analyses based on whole plastomes and nrDNA strongly support that the five species formed a monophyletic clade. Moreover, interspecific delimitation was well resolved except C. minus, individuals of which clustered into two main clades corresponding to their geographic distributions. The topology inferred from the nrDNA dataset was not congruent with the tree derived from the analyses of the plastid dataset. CONCLUSION: These findings represent the first important step in elucidating plastome evolution in this widespread distribution genus Cerotastigma in the Qinghai-Tibet Plateau. The detailed information could provide a valuable resource for understanding the molecular dynamics and phylogenetic relationship in the family Plumbaginaceae. Lineage genetic divergence within C. minus was perhaps promoted by geographic barriers in the Himalaya and Hengduan Mountains region, but introgression or hybridization could not be completely excluded.

Modified Patent Hemostasis Strategy Based on the Platelet Counts for Transradial Access Chemoembolization in Patients with Hepatocellular Carcinoma: A Prospective Single-Center Study.

Objective: This study aimed to investigate the shortest compression time to achieve hemostasis and the optimal hemostasis strategy in patients treated with transradial access chemoembolization (TRA-TACE). Methods: From October 2019 to October 2021, 119 consecutive patients with hepatocellular carcinoma (HCC) who underwent 134 sessions of TRA-TACE were included in this prospective single-center study. The compression time was measured by decompressing the device for 30 min, and thereafter, every 10 min after the procedure until complete hemostasis was achieved. Results: Technical success was achieved for all TRA procedures. None of the patients experienced major TRA-related adverse events. Minor adverse events occurred in 7.5% of the patients. The mean compression time was 31.8 ± 5.0 min. Factors that may impact hemostasis were analyzed by univariate and multivariate analyses, and a platelet count < 100×109 /L (p = 0.016, odds ratio = 3.942) was found to be an independent factor that could predict the failure to achieve hemostasis within 30 min. For patients with a platelet count < 100×109 /L, the compression time required to achieve hemostasis was 60 min. For patients with a platelet count ≥ 100×109 /L, the compression time required to achieve hemostasis was 40 min. Conclusion: To achieve hemostasis in patients with HCC treated with TRA-TACE, compression for 60 min is sufficient for those with a platelet count < 100×109 /L, and compression for 40 min is sufficient for those with a platelet count ≥ 100×109 /L.

Room-Temperature Magnetic Skyrmions and Large Topological Hall Effect in Chromium Telluride Engineered by Self-Intercalation.

Room-temperature magnetic skyrmion materials exhibiting robust topological Hall effect (THE) are crucial for novel nano-spintronic devices. However, such skyrmion-hosting materials are rare in nature. In this study, a self-intercalated transition metal dichalcogenide Cr1+ x Te2 with a layered crystal structure that hosts room-temperature skyrmions and exhibits large THE is reported. By tuning the self-intercalate concentration, a monotonic control of Curie temperature from 169 to 333 K and a magnetic anisotropy transition from out-of-plane to the in-plane configuration are achieved. Based on the intercalation engineering, room-temperature skyrmions are successfully created in Cr1.53 Te2 with a Curie temperature of 295 K and a relatively weak perpendicular magnetic anisotropy. Remarkably, a skyrmion-induced topological Hall resistivity as large as ≈106 nΩ cm is observed at 290 K. Moreover, a sign reversal of THE is also found at low temperatures, which can be ascribed to other topological spin textures having an opposite topological charge to that of the skyrmions. Therefore, chromium telluride can be a new paradigm of the skyrmion material family with promising prospects for future device applications.

3D Interconnected Magnetic Nanowire Networks as Potential Integrated Multistate Memristors.

Interconnected magnetic nanowire (NW) networks offer a promising platform for three-dimensional (3D) information storage and integrated neuromorphic computing. Here we report discrete propagation of magnetic states in interconnected Co nanowire networks driven by magnetic field and current, manifested in distinct magnetoresistance (MR) features. In these networks, when only a few interconnected NWs were measured, multiple MR kinks and local minima were observed, including a significant minimum at a positive field during the descending field sweep. Micromagnetic simulations showed that this unusual feature was due to domain wall (DW) pinning at the NW intersections, which was confirmed by off-axis electron holography imaging. In a complex network with many intersections, sequential switching of nanowire sections separated by interconnects was observed, along with stochastic characteristics. The pinning/depinning of the DWs can be further controlled by the driving current density. These results illustrate the promise of such interconnected networks as integrated multistate memristors.

Ultrasensitive Sub-monolayer Palladium Induced Chirality Switching and Topological Evolution of Skyrmions.

Chiral spin textures are fundamentally interesting, with promise for device applications. Stabilizing chirality is conventionally achieved by introducing Dzyaloshinskii-Moriya interaction (DMI) in asymmetric multilayers, where the thickness of each layer is at least a few monolayers. Here we report an ultrasensitive chirality switching in (Ni/Co)n multilayer induced by capping with only 0.22 monolayer of Pd. Using spin-polarized low-energy electron microscopy, we monitor the gradual evolution of domain walls from left-handed to right-handed Néel walls and quantify the DMI induced by the Pd capping layer. We also observe the chiral evolution of a skyrmion during the DMI switching, where no significant topological protection is found as the skyrmion winding number varies. This corresponds to a minimum energy cost of <1 attojoule during the skyrmion chirality switching. Our results demonstrate the detailed chirality evolution within skyrmions during the DMI sign switching, which is relevant to practical applications of skyrmionic devices.

Magnetic Skyrmions with Unconventional Helicity Polarization in a Van Der Waals Ferromagnet.

Skyrmion helicity, which defines the spin swirling direction, is a fundamental parameter that may be utilized to encode data bits in future memory devices. Generally, in centrosymmetric ferromagnets, dipole skyrmions with helicity of -π/2 and π/2 are degenerate in energy, leading to equal populations of both helicities. On the other hand, in chiral materials where the Dzyaloshinskii-Moriya interaction (DMI) prevails and the dipolar interaction is negligible, only a preferred helicity is selected by the type of DMI. However, whether there is a rigid boundary between these two regimes remains an open question. Herein, the observation of dipole skyrmions with unconventional helicity polarization in a van der Waals ferromagnet, Fe5- δ GeTe2 , is reported. Combining magnetometry, Lorentz transmission electron microscopy, electrical transport measurements, and micromagnetic simulations, the short-range superstructures in Fe5- δ GeTe2 resulting in a localized DMI contribution, which breaks the degeneracy of the opposite helicities and leads to the helicity polarization, is demonstrated. Therefore, the helicity feature in Fe5- δ GeTe2 is controlled by both the dipolar interaction and DMI that the former leads to Bloch-type skyrmions with helicity of ±π/2 whereas the latter breaks the helicity degeneracy. This work provides new insights into the skyrmion topology in van der Waals materials.

Effects of Early TACE Refractoriness on Survival in Patients with Hepatocellular Carcinoma: A Real-World Study.

Purpose: To investigate the effect of early transarterial chemoembolization (TACE) refractoriness on hepatocellular carcinoma (HCC) patient survival and to explore whether viable lesions > 50% after two consecutive TACE treatments negatively affect the prognosis of HCC patients. Patients and Methods: From January 2014 to August 2017, 323 HCC patients who received TACE as the initial treatment were analyzed. TACE refractoriness was diagnosed according to the Japan Society of Hepatology 2021 version. Propensity score matching (PSM) was used to create a 1:1 matched group (nonrefractoriness vs refractoriness). To determine survival outcomes and prognostic factors, the Kaplan-Meier method and Cox proportional hazards model were used. Results: In total, 51.1% of patients developed early TACE refractoriness (n = 165). After PSM, 120 patients from each group were matched and analyzed. The median overall survival (OS) time of the early TACE refractoriness group was significantly shorter than that of the nonrefractory group [21 months (95% CI: 15.7-26.3) vs 34 months (95% CI: 27.5-40.5), p = 0.002]. Thirty-eight patients with viable lesions >50% after two consecutive TACE procedures were identified and matched with patients of non-refractoriness. No significant difference in median OS was observed [35 months (95% CI: 21.6-48.5) vs 31 months (95% CI: 25.4-36.6), p = 0.611]. Multivariate analysis revealed that the BCLC stage, tumor size, tumor capsule, tumor distribution, α-fetoprotein level (AFP), and early TACE refractoriness were independent risk factors for prognosis in HCC patients. Conclusion: Early TACE refractoriness may shorten the OS of HCC patients. However, viable lesions >50% after two consecutive TACE treatments did not impair the survival of patients. It may be inappropriate to consider these patients as having developed TACE refractoriness.

Probing the mesoscopic size limit of quantum anomalous Hall insulators.

The inelastic scattering length (Ls) is a length scale of fundamental importance in condensed matters due to the relationship between inelastic scattering and quantum dephasing. In quantum anomalous Hall (QAH) materials, the mesoscopic length scale Ls plays an instrumental role in determining transport properties. Here we examine Ls in three regimes of the QAH system with distinct transport behaviors: the QAH, quantum critical, and insulating regimes. Although the resistance changes by five orders of magnitude when tuning between these distinct electronic phases, scaling analyses indicate a universal Ls among all regimes. Finally, mesoscopic scaled devices with sizes on the order of Ls were fabricated, enabling the direct detection of the value of Ls in QAH samples. Our results unveil the fundamental length scale that governs the transport behavior of QAH materials.

[Comparison of Clinical Efficacy of Thermal Ablation vs. Surgical Resection of Metachronous Colorectal Liver Metastasis].

Objective: To compare the treatment efficacy of thermal ablation versus surgical resection of metachronous colorectal liver metastasis (CRLM) and to explore the potential candidates suited for thermal ablation. Methods: The data of 319 patients with CRLM who underwent radical treatment at the Cancer Hospital, Chinese Academy of Medical Sciences between November 2007 and January 2021 were retrospectively collected. The patients were divided into two groups, the thermal ablation group and the surgical resection group, according to the actual treatments they received. Propensity score matching (PSM) was applied to balance the baseline characteristics between the two groups. Cox regression analysis was conducted to identify the risk factors for recurrence and survival. Survival analysis was performed for intergroup comparison. Results: Using PSM at 1∶1 ratio, 92 patients were included in the thermal ablation group and 92 patients were included in the surgical resection group.The median overall survival (OS) in the thermal ablation group was 49 (95% confidence interval, 37-76) months, which was shorter than that of the surgical resection group ( P<0.01). Multivariate Cox regression analysis indicated that the T staging of primary tumor, number of metastatic tumor, maximum diameter of metastatic tumor, preoperative serum carcinoembryonic antigen (CEA) level, and treatment method were independent risk factors affecting OS. Compared with the surgical resection group, the thermal ablation group demonstrated higher hepatic recurrence rate (59.8% vs. 23.9%, P<0.01), shorter disease-free survival (DFS) (10 months vs. 33 months, P<0.01), and shorter length of hospital stay (7 days vs. 14 days, P<0.01). Subgroup analysis, conducted with the data of the 319 patients before PSM, showed that early recurrence patients who underwent thermal ablation or surgical resection had comparable median OS (29 months vs. 42 months, P=0.35). For the non-early recurrence patients, the median OS of the thermal ablation group was shorter than that of the surgical resection group ( P<0.01). Conclusion: For the treatment of CRLM, the efficacy of surgical resection was better than that of thermal ablation. However, the efficacy was comparable between the two treatments for early recurrence patients of CRLM.

A Van der Waals Interface Hosting Two Groups of Magnetic Skyrmions.

Multiple magnetic skyrmion phases add an additional degree of freedom for skyrmion-based ultrahigh-density spin memory devices. Extending the field to 2D van der Waals magnets is a rewarding challenge, where the realizable degree of freedoms (e.g., thickness, twist angle, and electrical gating) and high skyrmion density result in intriguing new properties and enhanced functionality. In this work, a van der Waals interface, formed by two 2D ferromagnets Cr2 Ge2 Te6 and Fe3 GeTe2 with a Curie temperature of ≈65 and ≈205 K, respectively, hosting two groups of magnetic skyrmions, is reported. Two sets of topological Hall effect signals are observed below 6s0 K when Cr2 Ge2 Te6 is magnetically ordered. These two groups of skyrmions are directly imaged using magnetic force microscopy, and supported by micromagnetic simulations. Interestingly, the magnetic skyrmions persist in the heterostructure with zero applied magnetic field. The results are promising for the realization of skyrmionic devices based on van der Waals heterostructures hosting multiple skyrmion phases.

Effects of porcine acellular dermal matrix combined with human epidermal stem cells on wound healing of full-thickness skin defect in nude mice / 中华烧伤杂志

Objective: To explore the effects of porcine acellular dermal matrix (ADM) combined with human epidermal stem cells (ESCs) on wound healing of full-thickness skin defect in nude mice. Methods: The morphology of porcine ADM was analyzed by photograph of digital camera, the cell residues in porcine ADM were observed by hematoxylin-eosin (HE) staining, the surface structure of porcine ADM was observed by scanning electron microscope, the secondary structure of porcine ADM was analyzed by infrared spectrometer, the porcine ADM particle size was analyzed by dynamic light scattering particle size analyzer, and the porcine ADM potential was analyzed by nano-particle size potentiometer. The morphology of porcine ADM was observed by inverted fluorescence microscope when it was placed in culture medium for 30 min, 1 d, and 5 d (n=2). The porcine ADM was divided into 5 min group, 10 min group, 20 min group, 30 min group, 60 min group, and 120 min group according to the random number table (the same grouping method below) in static state at normal temperature for the corresponding time to calculate the water absorption by weighing method (n=3). Swiss white mouse embryonic fibroblasts (Fbs) were divided into blank control group (culture medium only), and 50.0 g/L ADM extract group, 37.5 g/L ADM extract group, 25.0 g/L ADM extract group, 12.5 g/L ADM extract group, and 6.5 g/L ADM extract group which were added with the corresponding final concentrations of ADM extract respectively. At post culture hour (PCH) 24, 48, and 72, the cell survival rate was detected by cell counting kit 8 and the cytotoxicity was graded (n=5). The erythrocytes of a 6-week-old male Sprague-Dawley male rat were divided into normal saline group, ultra-pure water group, and 5 mg/mL ADM extract group, 10 mg/mL ADM extract group, and 15 mg/mL ADM extract group which were treated with the corresponding final concentrations of porcine ADM extract respectively. After reaction for 3 h, the absorbance value of hemoglobin was detected by microplate reader to represent the blood compatibility of porcine ADM (n=3). ESCs were isolated and cultured from the discarded prepuce of a 6-year-old healthy boy who was treated in the Department of Urology of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) in July 2020, and then identified by flow cytometry. The porcine ADM particles of composite ESC (hereinafter referred to as ESC/ADM) were constructed by mixed culture. After 3 days of culture, the composite effect of ESC/ADM was observed by HE staining and laser scanning confocal microscope. Thirty-six 7-8-week-old male non-thymic nude mice were divided into phosphate buffer solution (PBS) alone group, ADM alone group, ESC alone group, and ESC/ADM group, with 9 mice in each group, and the wound model of full-thickness skin defect was established. Immediately after injury, the wounds were treated with the corresponding reagents at one time. On post injury day (PID) 1, 7, 11, and 15, the wound healing was observed and the wound healing rate was counted (n=3). On PID 7, the epithelialization of wounds was observed by HE staining and the length of un-epithelialized wound was measured (with this and the following sample numbers of 4). On PID 11, the dermal area and collagen deposition of wounds were observed by Masson staining and the dermal area of wound section was calculated, the number of cells expressing CD49f, a specific marker of ESC, was calculated with immunofluorescence staining, the mRNA expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in ESC after wound transplantation was detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, and least significant difference t test. Results: The porcine ADM was white particles and composed of reticular structure, with no cells inside, disordered structure, and rough surface. The absorption peak of porcine ADM appeared at the wave numbers of 1 659, 1 549, and 1 239 cm-1, respectively. The main particle size distribution of porcine ADM in solution was 500 to 700 nm, with negative charge on the surface. The morphology of porcine ADM in static state at 30 min and on 1 and 5 d was relatively stable. The water absorption of porcine ADM remained relatively high level in static state from 30 min to 120 min. The cytotoxicity of mouse embryonic Fbs in 6.5 g/L ADM extract group, 12.5 g/L ADM extract group, and 25.0 g/L ADM extract group was grade 1 at PCH 24, and the cytotoxicity of the other groups was 0 grade at each time point. After reaction for 3 h, the absorbance value of hemoglobin of erythrocytes in ultra-pure water group was significantly higher than the values in normal saline group and 15 mg/mL ADM extract group (with t values of 8.14 and 7.96, respectively, P<0.01). After 3 days of culture, the cells of the fourth passage showed pebble-like morphology, with low expression of CD71 and high expression of CD49f, which were identified as ESCs. There was ESC attachment and growth on porcine ADM particles. On PID 1, the wound sizes of nude mice were almost the same in PBS alone group, ADM alone group, ESC alone group, and ESC/ADM group. On PID 7, 11, and 15, the wound contraction of nude mice in each group was observed, especially in ADM alone group, ESC alone group, and ESC/ADM group. On PID 7, the wound healing rates of nude mice in ESC alone group and ESC/ADM group were significantly higher than the rate in PBS alone group (with t values of 2.83 and 4.72 respectively, P<0.05 or P<0.01). On PID 11, the wound healing rate of nude mice in ESC/ADM group was significantly higher than that in PBS alone group (t=4.86, P<0.01). On PID 15, the wound healing rates of nude mice in ADM alone group, ESC alone group, and ESC/ADM group were significantly higher than the rate in PBS alone group (with t values of 2.71, 2.90, and 3.23 respectively, P<0.05). On PID 7, the length of un-epithelialized wound of nude mice in ADM alone group, ESC alone group, and ESC/ADM group was (816±85), (635±66), and (163±32) μm, respectively, which were significantly shorter than (1 199±43) μm in PBS alone group (with t values of 5.69, 10.19, and 27.54 respectively, P<0.01). On PID 11, the dermal areas of wound section of nude mice in ADM alone group, ESC alone group, and ESC/ADM group were significantly larger than the area in PBS alone group (with t values of 27.14, 5.29, and 15.90 respectively, P<0.01); the collagen production of nude mice in ADM alone group and ESC/ADM group was more obvious than that in PBS alone group, and the collagen production of nude mice in ESC alone group and PBS alone group was similar. On PID 11, in the wounds of nude mice in ESC alone group and ESC/ADM group, the cells with positive expression of CD49f were respectively 135±7 and 185±15, and the mRNA expressions of GAPDH were positive; while there were no expressions of CD49f nor mRNA of GAPDH in the wounds of nude mice in PBS alone group and ADM alone group. Conclusions: ESC/ADM particles can promote the wound healing of full-thickness skin defects in nude mice, which may be related to the improved survival rate of ESCs after transplantation and the promotion of dermal structure rearrangement and angiogenesis by ADM.

Two novel mutations in TCIRG1 induced infantile malignant osteopetrosis: a case report.

BACKGROUND: Infantile malignant osteopetrosis (IMO) is a rare autosomal recessive disease characterized by a higher bone density in bone marrow caused by the dysfunction of bone resorption. Clinically, IMO can be diagnosed with medical examination, bone mineral density test and whole genome sequencing. CASE PRESENTATION: We present the case of a 4-month-old male infant with abnormal skull development, hypocalcemia and premature closure of the cranial sutures. Due to the hyper bone density showed by his radiographic examination, which are characteristic patterns of IMO, we speculated that he might be an IMO patient. In order to confirm this diagnosis, a high-precision whole exome sequencing of the infant and his parents was performed. The analysis of high-precision whole exome sequencing results lead to the identification of two novel heterozygous mutations c.504-1G > C (a splicing site mutation) and c.1371delC (p.G458Afs*70, a frameshift mutation) in gene TCIRG1 derived from his parents. Therefore, we propose that there is a close association between these two mutations and the onset of IMO. CONCLUSIONS: To date, these two novel mutations in gene TCIRG1 have not been reported in the reference gene database of Chinese population. These variants have likewise not been reported outside of China in the Genome Aggregation Database (gnomAD). Our case suggests that the use of whole exome sequencing to detect these two mutations will improve the identification and early diagnosis of IMO, and more specifically, the identification of homozygous individuals with TCIRG1 gene mutation. We propose that these mutations in gene TCIRG1 could be a novel therapeutic target for the IMO in the future.