[Clinical characteristics of children with severe SARS-CoV-2 infection in Yunnan]

Objective: To investigate the clinical characteristics of 130 children with severe SARS-CoV-2 infection in Yunnan province after the relaxation of non-pharmaceutical interventions, and analyze the risk factors for mortality. Methods: This study is a retrospective case summary that analyzed the demographic data, underlying diseases, clinical diagnoses, disease outcomes, and laboratory results of 130 children with severe COVID-19 infections admitted to nine top-tier hospitals in Yunnan Province from December 2022 to March 2023. According to the prognosis, the patients were divided into survival group and death group. The clinical and laboratory data between the two groups were compared, and the risk factors of death were evaluated. The χ2 test and Mann-Whitney U test were employed to compare between groups, while Spearman correlation test and multiple Logistic regression were used to analyze the risk factors for death. The predictive value of independent risk factors was evaluated by receiver operating characteristic curve. Results: The 130 severe patients included 80 males and 50 females with an onset age of 28.0 (4.5, 79.5) months. There were 97 cases in the survival group and 33 cases in the death group with no significant differences in gender and age between the two groups (P>0.05). Twenty-five cases (19.2%) out of the 130 patients had underlying diseases, and the number with underlying diseases was significantly higher in death group than in survival group (36.4% (12/33) vs. 13.4%(13/97), χ2=8.36, P=0.004). The vaccination rate in the survival group was significantly higher than that in the death group (86.1% (31/36) vs. 7/17, χ2=9.38, P=0.002). A total of 42 cases (32.3%) of the 130 patients were detected to be infected with other pathogens, but there was no significant difference in the incidence of co-infection between the death group and the survival group (39.3%(13/33) vs. 29.9% (29/97), χ2=1.02, P>0.05). Among the 130 cases, severe respiratory cases were the most common 66 cases (50.8%), followed by neurological severe illnesses 34 cases (26.2%) and circulatory severe 13 cases (10%). Compared to the survival group, patients in the death group had a significantly higher levels of neutrophil, ferritin, procalcitonin, alanine aminotransferase, lactate dehydrogenase, creatine kinase isoenzyme, B-type natriuretic peptide, interleukin-6 and 10 (6.7 (4.0, 14.0) vs. 3.0 (1.6, 7.0)×109/L, 479 (298, 594) vs. 268 (124, 424) μg/L, 4.8 (1.7, 10.6) vs. 2.0 (1.1, 3.1) μg/L, 66 (20, 258) vs. 23 (15, 49) U/L, 464 (311, 815) vs. 304 (252, 388) g/L, 71(52, 110) vs. 24(15, 48) U/L, 484 (160, 804) vs. 154 (26, 440) ng/L, 43 (23, 102) vs. 19 (13, 27) ng/L, 216 (114, 318) vs. 86 (45, 128) ng/L, Z=-4.21, -3.67, -3.76, -3.31, -3.75, -5.74, -3.55, -4.65, -5.86, all P<0.05). The correlated indexes were performed by multivariate Logistic regression and the results showed that vaccination was a protective factor from death in severe cases (OR=0.01, 95%CI 0-0.97, P=0.049) while pediatric sequential organ failure assessment (PSOFA) (OR=3.31, 95%CI 1.47-7.47, P=0.004), neutrophil-to-lymphocyte ratio (NLR) (OR=1.56, 95%CI 1.05-2.32, P=0.029) and D dimer (OR=1.49, 95%CI 1.00-1.02, P=0.033) were independent risk factors for death (all P<0.05). The area under the curve of the three independent risk factors for predicting death were 0.86 (95%CI 0.79-0.94), 0.89 (95%CI 0.84-0.95) and 0.87 (95%CI 0.80-0.94), all P<0.001, and the cut-off values were 4.50, 3.66 and 4.69 mg/L, respectively. Conclusions: Severe SARS-CoV-2 infection can occur in children of all ages, primarily affecting the respiratory system, but can also infect the nervous system, circulatory system or other systems. Children who died had more severe inflammation, tissue damage and coagulation disorders. The elevations of PSOFA, NLR and D dimer were independent risk factors for death in severe children.

Round ligament management during minimally invasive groin hernia repair in women: a systematic review and meta-analysis

BACKGROUND

Female sex has been associated with worse outcomes after groin hernia repair (GHR), including a higher rate of chronic pain and recurrence. Most of the studies in GHR are performed in males, and the recommendations for females extrapolate from these studies, even though females have anatomy intricacies. The round ligament of the uterus (RLU) is associated with pelvic stabilization and plays a role in sensory function. Transection of the RLU during GHR is controversial as it can allow easier mesh placement but can favor genitourinary complications and chronic pain. As no previous meta-analysis compared preserving versus transecting the RLU during minimally invasive (MIS) GHR, we aim to perform a systematic review and meta-analysis evaluating surgical outcomes comparing the approaches.

METHODS

Cochrane Central, Embase, and PubMed databases were systematically searched for studies comparing transection versus preservation of the RLU in MIS groin hernia surgeries. Outcomes assessed were operative time, bleeding, surgical site events, hospital stay, chronic pain, paresthesia, recurrence rates, and genital prolapse rates. Statistical analysis was performed using RevMan 5.4.1. Heterogeneity was assessed with I2 statistics. A review protocol for this meta-analysis was registered at PROSPERO (CRD 42023467146).

RESULTS

1738 studies were screened. A total of six studies, comprising 1131 women, were included, of whom 652 (57.6%) had preservation of the RLU during MIS groin hernia repair. We found no statistical difference regarding chronic pain, paresthesia, recurrence rates, and postoperative complications. We found a longer operative time for the preservation group (MD 6.84 min; 95% CI 3.0-10.68; P = 0.0005; I2 = 74%).

CONCLUSION

Transecting the RLU reduces the operative time during MIS GHR with no difference regarding postoperative complication rates. Although transection appears safe, further prospective randomized studies with long-term follow-up and patient-reported outcomes are necessary to define the optimal management of RLU during MIS GHR.

Longitudinal profiling identifies co-occurring BRCA1/2 reversions, TP53BP1, RIF1 and PAXIP1 mutations in PARP inhibitor-resistant advanced breast cancer

BACKGROUND

Resistance to therapies that target homologous recombination deficiency (HRD) in breast cancer limits their overall effectiveness. Multiple, preclinically validated, mechanisms of resistance have been proposed, but their existence and relative frequency in clinical disease are unclear, as is how to target resistance.

PATIENTS AND METHODS

Longitudinal mutation and methylation profiling of circulating tumour (ct)DNA was carried out in 47 patients with metastatic BRCA1-, BRCA2- or PALB2-mutant breast cancer treated with HRD-targeted therapy who developed progressive disease-18 patients had primary resistance and 29 exhibited response followed by resistance. ctDNA isolated at multiple time points in the patient treatment course (before, on-treatment and at progression) was sequenced using a novel >750-gene intron/exon targeted sequencing panel. Where available, matched tumour biopsies were whole exome and RNA sequenced and also used to assess nuclear RAD51.

RESULTS

BRCA1/2 reversion mutations were present in 60% of patients and were the most prevalent form of resistance. In 10 cases, reversions were detected in ctDNA before clinical progression. Two new reversion-based mechanisms were identified: (i) intragenic BRCA1/2 deletions with intronic breakpoints; and (ii) intragenic BRCA1/2 secondary mutations that formed novel splice acceptor sites, the latter being confirmed by in vitro minigene reporter assays. When seen before commencing subsequent treatment, reversions were associated with significantly shorter time to progression. Tumours with reversions retained HRD mutational signatures but had functional homologous recombination based on RAD51 status. Although less frequent than reversions, nonreversion mechanisms [loss-of-function (LoF) mutations in TP53BP1, RIF1 or PAXIP1] were evident in patients with acquired resistance and occasionally coexisted with reversions, challenging the notion that singular resistance mechanisms emerge in each patient.

CONCLUSIONS

These observations map the prevalence of candidate drivers of resistance across time in a clinical setting, information with implications for clinical management and trial design in HRD breast cancers.

Transinguinal preperitoneal (TIPP) versus Lichtenstein for inguinal hernia repair: a systematic review and meta-analysis

PURPOSE

We aimed to perform a systematic review and meta-analysis comparing postoperative outcomes in inguinal hernia repair with TIPP versus Lichtenstein technique.

METHODS

Cochrane Central, Scopus, and PubMed were systematically searched for studies comparing TIPP and Lichtenstein´s technique for inguinal hernia repair. Outcomes assessed were operative time, bleeding, surgical site events, hospital stay, the Visual Analogue Pain Score, chronic pain, paresthesia rates, and recurrence. Statistical analysis was performed using RevMan 5.4.1. Heterogeneity was assessed with I2 statistics and random-risk effect was used if I2 > 25%.

RESULTS

790 studies were screened and 44 were thoroughly reviewed. A total of nine studies, comprising 8428 patients were included, of whom 4185 (49.7%) received TIPP and 4243 (50.3%) received Lichtenstein. We found that TIPP presented less chronic pain (OR 0.43; 95% CI 0.20-0.93 P = 0.03; I2 = 84%) and paresthesia rates (OR 0.27; 95% CI 0.07-0.99; P = 0.05; I2 = 63%) than Lichtenstein group. In addition, TIPP was associated with a lower VAS pain score at 14 postoperative day (MD - 0.93; 95% CI - 1.48 to - 0.39; P = 0.0007; I2 = 99%). The data showed a lower operative time with the TIPP technique (MD - 7.18; 95% CI - 12.50, - 1.87; P = 0.008; I2 = 94%). We found no statistical difference between groups regarding the other outcomes analyzed.

CONCLUSION

TIPP may be a valuable technique for inguinal hernias. It was associated with lower chronic pain, and paresthesia when compared to Lichtenstein technique. Further long-term randomized studies are necessary to confirm our findings. Study registration A review protocol for this meta-analysis was registered at PROSPERO (CRD42023434909).

Mesh repair versus non-mesh repair for incarcerated and strangulated groin hernia: an updated systematic review and meta-analysis

BACKGROUND

Mesh repair in incarcerated or strangulated groin hernia is controversial, especially when bowel resection is required. We aimed to perform a meta-analysis comparing mesh and non-mesh repair in patients undergoing emergency groin hernia repair.

METHODS

We performed a literature search of databases to identify studies comparing mesh and primary suture repair of patients with incarcerated or strangulated inguinal or femoral hernias who underwent emergency surgery. Postoperative outcomes were assessed by pooled analysis and meta-analysis. Statistical analysis was performed using RevMan 5.4. Heterogeneity was assessed with I2 statistics.

RESULTS

1095 studies were screened and 101 were thoroughly reviewed. Twenty observational studies and four randomized controlled trials comprising 12,402 patients were included. We found that mesh-based repair had reduced recurrence (OR 0.36; 95% CI 0.19, 0.67; P = 0.001; I2 = 35%), length of hospital stay (OR - 1.02; 95% CI - 1.87, - 0.17; P = 0.02; I2 = 94%) and operative time (OR - 9.21; 95% CI - 16.82, - 1.61; P = 0.02; I2 = 95%) without increasing surgical site infection, mortality or postoperative complications such as seroma, chronic, ileus or urinary retention. In the subgroup analysis of patients that underwent bowel resection, we found that mesh repair was associated with an increased risk of surgical site infection (OR 1.74; 95% CI 1.04, 2.91; P = 0.04; I2 = 9%).

CONCLUSIONS

Mesh repair for incarcerated and strangulated groin hernias reduces recurrence without an increase in postoperative complications and should be considered in clean cases. However, in the setting of bowel resection, mesh repair might increase the incidence of surgical site infection.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Management and outcomes of obturator hernias: a systematic review and meta-analysis

PURPOSE

Obturator Hernia (OH) is a rare type of abdominal wall hernia. It usually occurs in elderly women with late symptomatic presentation, increasing mortality rates. Surgery is the standard of care for OH, and laparotomy with simple suture closure of the defect is commonly used. Given the rarity of this disease, large studies are lacking, and data to drive management are still limited. This systematic review and meta-analysis aimed to describe current surgical options for OHs, with a focus on comparing the effectiveness and safety of mesh use with primary repair.

METHODS

PubMed, EMBASE, and Cochrane were searched for studies comparing mesh and non-mesh repair for OH. Postoperative outcomes were assessed by pooled analysis and meta-analysis. Statistical analysis was performed using RevMan 5.4.

RESULTS

One thousand seven hundred and sixty studies were screened and sixty-seven were thoroughly reviewed. We included 13 observational studies with 351 patients surgically treated for OH with mesh or non-mesh repair. One hundred and twenty (34.2%) patients underwent mesh repair and two hundred and thirty-one (65.81%) underwent non-mesh repair. A total of 145 (41.3%) underwent bowel resection, with the majority having a non-mesh repair performed. Hernia recurrence was significantly higher in patients who underwent hernia repair without mesh (RR 0.31; 95% CI 0.11-0.94; p = 0.04). There were no differences in mortality (RR 0.64; 95% CI 0.25-1.62; p = 0.34; I² = 0%) or complication rates (RR 0.59; 95% CI 0.28-1.25; p = 0.17; I² = 50%) between both groups.

CONCLUSION

Mesh repair in OH was associated with lower recurrence rates without an increase in postoperative complications. While mesh in clean cases is more likely to offer benefits, an overall recommendation regarding its use in OH repair cannot be made due to potential bias across studies. Given that many OH patients are frail and present emergently, the decision to use mesh is complex and should consider the patient's clinical status, comorbidities, and degree of intraoperative contamination.

Integrating EM and Patch-seq data: Synaptic connectivity and target specificity of predicted Sst transcriptomic types

Neural circuit function is shaped both by the cell types that comprise the circuit and the connections between those cell types ¹ . Neural cell types have previously been defined by morphology ^{2, 3} , electrophysiology ^{4, 5} , transcriptomic expression ^6-8 , connectivity ^9-13 , or even a combination of such modalities ^14-16 . More recently, the Patch-seq technique has enabled the characterization of morphology (M), electrophysiology (E), and transcriptomic (T) properties from individual cells ^17-20 . Using this technique, these properties were integrated to define 28, inhibitory multimodal, MET-types in mouse primary visual cortex ²¹ . It is unknown how these MET-types connect within the broader cortical circuitry however. Here we show that we can predict the MET-type identity of inhibitory cells within a large-scale electron microscopy (EM) dataset and these MET-types have distinct ultrastructural features and synapse connectivity patterns. We found that EM Martinotti cells, a well defined morphological cell type ^{22, 23} known to be Somatostatin positive (Sst+) ^{24, 25} , were successfully predicted to belong to Sst+ MET-types. Each identified MET-type had distinct axon myelination patterns and synapsed onto specific excitatory targets. Our results demonstrate that morphological features can be used to link cell type identities across imaging modalities, which enables further comparison of connectivity in relation to transcriptomic or electrophysiological properties. Furthermore, our results show that MET-types have distinct connectivity patterns, supporting the use of MET-types and connectivity to meaningfully define cell types.

A computational model for the transit of a cancer cell through a constricted microchannel

We propose a three-dimensional computational model to simulate the transient deformation of suspended cancer cells flowing through a constricted microchannel. We model the cell as a liquid droplet enclosed by a viscoelastic membrane, and its nucleus as a smaller stiffer capsule. The cell deformation and its interaction with the suspending fluid are solved through a well-tested immersed boundary lattice Boltzmann method. To identify a minimal mechanical model that can quantitatively predict the transient cell deformation in a constricted channel, we conduct extensive parametric studies of the effects of the rheology of the cell membrane, cytoplasm and nucleus and compare the results with a recent experiment conducted on human leukaemia cells. We find that excellent agreement with the experiment can be achieved by employing a viscoelastic cell membrane model with the membrane viscosity depending on its mode of deformation (shear versus elongation). The cell nucleus limits the overall deformation of the whole cell, and its effect increases with the nucleus size. The present computational model may be used to guide the design of microfluidic devices to sort cancer cells, or to inversely infer cell mechanical properties from their flow-induced deformation.

Management of diastasis recti during ventral hernia repair: an analysis of the abdominal core health quality collaborative

PURPOSE

Advancements of minimally invasive techniques leveraged routine repair of concomitant diastasis recti (DR), as those approaches facilitate fascial plication and wide mesh overlap while obviating skin incision and/or undermining. Nevertheless, evidence on the value of such intervention is lacking. We aimed to investigate the management and outcomes of concomitant DR during ventral hernia repair (VHR + DR) from surgeons participating in the Abdominal Core Health Quality Collaborative (ACHQC).

METHODS

Patients who have undergone VHR + DR with a minimum 30-day follow-up complete were identified. Outcomes of interest included operative details, surgical site occurrences (SSO), medical complications, and readmissions.

RESULTS

169 patients (51% female, median age 46, median body mass index 31 kg/m2) were identified. Most hernias were primary (64% umbilical, 28% epigastric). Median hernia width was 3 cm (IQR 2-4) and median diastasis width and length were 4 cm (IQR 3-6) and 15 cm (IQR 10-20), respectively. Most operations were robotic (79%), with a synthetic mesh (92%) placed as a sublay (72%; 59% retromuscular, 13% preperitoneal). DR was repaired with absorbable (92%) and running suture (93%). Considering our cohort's relatively small diastasis and hernia size, a high rate of transversus abdominis release was noted (14.7%). 76% were discharged the same day and the 30-day readmission rate was 2% (2 ileus, 1 pneumonia). SSO rate was 4% (6 seromas, 1 skin necrosis) and only one patient required a procedural intervention.

CONCLUSIONS

ACHQC participating surgeons usually perform VHR + DR robotically with a retromuscular synthetic mesh and close the DR with running absorbable sutures. Short-term complications occurred in approximately 6% of patients and were mainly managed without interventions. Larger studies with longer-term follow-up are needed to determine the value of VHR + DR.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

[Efficacy analysis of selective genicular artery embolization in the treatment of knee pain secondary to osteoarthritis]

Objective: To evaluate the efficacy and safety of selective genicular artery embolization for the treatment of the knee pain secondary to osteoarthritis. Methods: From October 2020 to July 2021, 17 patients (23 knees) aged (68±7) years with moderate to severe knee pain secondary to knee osteoarthritis were prospectively included in the General Hospital of Ningxia Medical University. There were 6 males and 11 females included in this research. Patients were assessed with knee pain, stiffness, and function with the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline, using the Kellgren-Lawrence (K-L) grading to evaluate the severity of KOA, and using the Magnetic Resonance Knee Osteoarthritis Score (MOAKS) to evaluate the MR imaging characteristics of the affected knee. Selective genicular artery embolization (GAE) was performed in all patients. The patients were followed up for 6 months after the procedure. Patients were assessed with the VAS score and WOMAC scale at 1 d, 1 week and 1, 3 and 6 months after the procedure to evaluate the clinical outcomes, including the improvement of knee joint pain, stiffness and function, as well as the occurrence of adverse reactions. Results: Three to seven genicular artery branches were superselected and embolized in 23 knees, and 4 to 7 genicular artery branches were embolized in 7 patients with K-L grade 4. The clinical improvement was 95.6% (22/23) at 1 month, 86.9% (20/23) at 3 months, and 91.3% (21/23) at 6 months. Twenty-three knees completed the 6-month follow-up, and the VAS score, WOMAC pain score, and total WOMAC score at 1, 3, and 6 months after surgery were (2.5±1.3), (3.4±2.4), and (19.7±9.8) points, (3.0±1.8), (4.5±3.4), and (22.3±11.3) points, (2.8±1.5), (4.1±3.0), and (20.5±11.0) points, which were lower than the (6.6±0.9), (11.4±2.6) and (47.0±12.0) points at baseline (all P<0.001). During the follow-up period, 7 patients had adverse reactions: 3 cases had skin ecchymosis in the femoral artery puncture area, 4 cases had knee joint stiffness and pain within 1 day after operation, which were relieved spontaneously in 1 week, 6 patients had joint clicking during extension and flexion activities after operation, of which 3 cases subsided spontaneously within 3 months after operation. None of the patients had major procedure-related adverse events. Conclusion: GAE has a high clinical improvement rate and a low incidence of adverse reactions in the treatment of the pain secondary to knee osteoarthritis, which provides a new treatment option for patients who fail to respond to conservative treatment.

Per- and polyfluoroalkyl substances target and alter human prostate stem-progenitor cells

Per- and polyfluorinated alkyl substances (PFAS) are a large family of widely used synthetic chemicals that are environmentally and biologically persistent and present in most individuals. Chronic PFAS exposure have been linked to increased prostate cancer risk in occupational settings, however, underlying mechanisms have not been interrogated. Herein we examined exposure of normal human prostate stem-progenitor cells (SPCs) to 10 nM PFOA or PFOS using serial passage of prostasphere cultures. Exposure to either PFAS for 3-4 weeks increased spheroid numbers and size indicative of elevated stem cell self-renewal and progenitor cell proliferation. Transcriptome analysis using single-cell RNA sequencing (scRNA-seq) showed 1) SPC expression of PPARs and RXRs able to mediate PFAS effects, 2) the emergence of a new cell cluster of aberrantly differentiated luminal progenitor cells upon PFOS/PFOA exposure, and 3) enrichment of cancer-associated signaling pathways. Metabolomic analysis of PFAS-exposed prostaspheres revealed increased glycolytic pathways including the Warburg effect as well as strong enrichment of serine and glycine metabolism which may promote a pre-malignant SPC fate. Finally, growth of in vivo xenografts of tumorigenic RWPE-2 human prostate cells, shown to contain cancer stem-like cells, was markedly enhanced by daily PFOS feeding to nude mice hosts. Together, these findings are the first to identify human prostate SPCs as direct PFAS targets with resultant reprogrammed transcriptomes and metabolomes that augment a preneoplastic state and may contribute to an elevated prostate cancer risk with chronic exposures.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Clinical outcomes of keratinized mucosa augmentation in jaws reconstructed with fibula or iliac bone flaps

This prospective study was undertaken to evaluate the treatment outcomes of keratinized mucosa augmentation (KMA) on the buccal and palatal/lingual sides of implants in jaws reconstructed after oncological surgery. Forty-two implants in 12 patients whose jaws had been reconstructed with a fibula or iliac bone flap were included. KMA was performed at 3 months after implant placement; this included an apically displaced partial-thickness flap and a free gingival graft (FGG) around the implants to increase the keratinized mucosa width (KMW). Patients were followed up for at least 6 months post-surgery. KMW, shrinkage, and patient pain and discomfort measured on a visual analogue scale were analysed. A histological analysis was performed of tissue epithelium from two patients. The results showed that KMW was >2 mm on both the buccal and palatal/lingual sides during follow-up. Before surgery, histological analysis showed epithelium with no epithelial spikes; normal keratinized epithelial spikes were observed at 8 weeks after KMA. Greater KMW was observed around implants in reconstructed maxillae than around those in reconstructed mandibles (P < 0.001). Patients felt more pain at the donor site than at the recipient site during the first 3 days post-surgery. KMA with FGG was predictable in reconstructed jaws and may help maintain the long-term stability of implants.

Establishment and verification of a nomogram for predicting severe acute pancreatitis

OBJECTIVE

The purpose of this study was to establish a nomogram for predicting the severity of acute pancreatitis (AP) and verify its predictive value.

PATIENTS AND METHODS

A total of 571 AP patients received by Ordos Central Hospital from January 2015 to December 2018 were included in this study. According to the 2012 Revised Atlanta classification, the included subjects were classified into severe AP (SAP) group and non-severe AP (NSAP) group [including patient with mild AP (MAP) and moderately SAP (MSAP)]. The baseline characteristics, imageological data and pathological data within 24 h after the disease onset between the two groups were analyzed using One-way analysis of variance (one-way ANOVA). R language was used for establishing a predictive nomogram, whose performance was verified by clinical data of 150 AP cases collected from December 2018 to December 2019.

RESULTS

One-way ANOVA shows that SAP and NSAP patients show significant differences in sex, calcium ions, creatinine, neutrophils ratio, lymphocytes ratio and eosinophils ratio (p<0.05). A predictive nomogram was accordingly established using the six indicators. Validation on this predictive nomogram showed high internal validation concordance index (C-index) of 0.69 (95% CI, 0.64-0.74), and high external validation C-index of 0.71 (95% CI, 0.67-0.76).

CONCLUSIONS

This nomogram can be used as a clinical tool to predict the severity of SAP.

Keratin Profiling by Single-Cell RNA-Sequencing Identifies Human Prostate Stem Cell Lineage Hierarchy and Cancer Stem-Like Cells

Single prostate stem cells can generate stem and progenitor cells to form prostaspheres in 3D culture. Using a prostasphere-based label retention assay, we recently identified keratin 13 (KRT13)-enriched prostate stem cells at single-cell resolution, distinguishing them from daughter progenitors. Herein, we characterized the epithelial cell lineage hierarchy in prostaspheres using single-cell RNA-seq analysis. Keratin profiling revealed three clusters of label-retaining prostate stem cells; cluster I represents quiescent stem cells (PSCA, CD36, SPINK1, and KRT13/23/80/78/4 enriched), while clusters II and III represent active stem and bipotent progenitor cells (KRT16/17/6 enriched). Gene set enrichment analysis revealed enrichment of stem and cancer-related pathways in cluster I. In non-label-retaining daughter progenitor cells, three clusters were identified; cluster IV represents basal progenitors (KRT5/14/6/16 enriched), while clusters V and VI represent early and late-stage luminal progenitors, respectively (KRT8/18/10 enriched). Furthermore, MetaCore analysis showed enrichment of the “cytoskeleton remodeling–keratin filaments” pathway in cancer stem-like cells from human prostate cancer specimens. Along with common keratins (KRT13/23/80/78/4) in normal stem cells, unique keratins (KRT10/19/6C/16) were enriched in cancer stem-like cells. Clarification of these keratin profiles in human prostate stem cell lineage hierarchy and cancer stem-like cells can facilitate the identification and therapeutic targeting of prostate cancer stem-like cells.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.