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.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

[MRI evaluation of condylar bone regeneration after temporomandibular joint disc reduction and suture and analysis of factors affecting bone regeneration]

Objective: To evaluate the MRI manifestations of condylar bone regeneration after disc reduction and suture for anterior disc displacement without reduction (ADDWoR) patients and to analyze the relevant factors affecting bone regeneration. Methods: A total of 61 patients of 75 joints with ADDWoR who attended the Department of Maxillofacial Surgery of the Affiliated Hospital of Stomatology of Nanjing Medical University from April 2020 to December 2021 were enrolled in the study. The characteristics of MRI condylar bone regeneration were analyzed before and after surgery (follow-up for 6 months or more), and logistic regression analysis was performed on the influencing factors of bone regeneration. Results: The new bone formation of the condyle was found in 28 patients, with age of (20.2±4.9) years. However, there were 33 patients that had no condylar bone regeneration, with age of (41.9±17.5) years. A total of 35 joints in this study were found new bone formation. There were 16 joints (45.7%) had new bone formation on the posterior slope of the condyle, 10 joints (28.6%) around the condyle, 6 joints (17.1%) on the anterior slope of the condyle, and only 3 joints (8.6%) on the top of the condyle. Multivariate logistic regression analysis showed that age, preoperative disc length and degree of condylar bone resorption correlated with postoperative condylar bone regeneration(P<0.05). Patients younger than 30 years with non-shortened preoperative disc length and less condylar bone resorption have a higher probability of new bone formation. Conclusions: The condyle has bone regeneration capacity after correcting the abnormal relationship between disc and condyle, and young age, non-shortened preoperative disc length and less condylar bone resorption are conducive to postoperative condylar bone regeneration.

[Spatial and temporal distribution characteristics of seasonal A(H3N2) influenza in China, 2014-2019]

Objective: To analyze the spatial and temporal distribution characteristics of seasonal A(H3N2) influenza [influenza A(H3N2)] in China and to provide a reference for scientific prevention and control. Methods: The influenza A(H3N2) surveillance data in 2014-2019 was derived from China Influenza Surveillance Information System. A line chart described the epidemic trend analyzed and plotted. Spatial autocorrelation analysis was conducted using ArcGIS 10.7, and spatiotemporal scanning analysis was conducted using SaTScan 10.1. Results: A total of 2 603 209 influenza-like case sample specimens were detected from March 31, 2014, to March 31, 2019, and the influenza A(H3N2) positive rate was 5.96%(155 259/2 603 209). The positive rate of influenza A(H3N2) was statistically significant in the north and southern provinces in each surveillance year (all P<0.05). The high incidence seasons of influenza A (H3N2) were in winter in northern provinces and summer or winter in southern provinces. Influenza A (H3N2) clustered in 31 provinces in 2014-2015 and 2016-2017. High-high clusters were distributed in eight provinces, including Beijing, Tianjin, Hebei, Shandong, Shanxi, Henan, Shaanxi, and Ningxia Hui Autonomous Region in 2014-2015, and high-high clusters were distributed in five provinces including Shanxi, Shandong, Henan, Anhui, and Shanghai in 2016-2017. Spatiotemporal scanning analysis from 2014 to 2019 showed that Shandong and its surrounding twelve provinces clustered from November 2016 to February 2017 (RR=3.59, LLR=9 875.74, P<0.001). Conclusion: Influenza A (H3N2) has high incidence seasons with northern provinces in winter and southern provinces in summer or winter and obvious spatial and temporal clustering characteristics in China from 2014-2019.

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.

Simulating nitrogen balance in Canadian agricultural soils from 1981 to 2016

Agriculture produces food, fiber and biofuels for the world's growing population, however, agriculture can be a major contributor of nitrogen (N) losses including emissions of ammonia (NH₃), nitrous oxide (N₂O) and nitrate (NO₃^-) leaching and runoff. A Canadian Agricultural Nitrogen Budget for Reactive N (CANBNr) model was developed to estimate the soil N balance in 3487 soil landscape of Canada polygons from 1981 to 2016. The CANBNr model integrates NH₃ emission from fertilizers, manure from housing, storage and field, as well as direct/indirect N₂O emissions from fertilizers, manures, crop residues and soil organic matter. The NO₃^- leaching is estimated based on the residual soil N (RSN) at harvest and drainage derived with the DeNitrification-DeComposition (DNDC) model. From 1981 to 2016, the N input from fertilizer and N fixation increased at a greater rate than N removal in harvested crops in all provinces of Canada, resulting in an increase in the RSN and N losses. In 2016, the Prairie provinces had lower N losses (11.7 kg N ha^-1) from N₂O, NH₃ and NO₃^- compared with 43.2 kg N ha^-1 in central Canada, and 76.5 kg N ha^-1 in Atlantic Canada. However, the Prairie provinces had 84.3% of the total Canadian farmland (74.3% of the total Canadian N input), while central Canada had 12.9% of Canadian farmland (21.7% of the total Canadian N input). In the Prairie provinces, the total N₂O loss from fertilizer N ranged 4.4-8.6 Gg N whereas NH₃ loss ranged from 17.1 to 44.6 Gg N and these values were influenced by both emission intensity and total land area. Total N₂O losses from manure were highest in Alberta, Ontario and Quebec resulting in 4.8, 4.4, and 3.4 Gg N and NH₃ losses from manure were also highest in these 3 provinces at 61.1, 45.2 and 40.4 Gg N, respectively. Nitrate leaching was impacted by drainage volumes, soil type and N inputs. In the non-growing season, NO₃^- leaching losses (36-yr average) were 63.3 Gg in Ontario and 57.5 Gg N in Quebec compared with 20.8 Gg N for Ontario and 35.5 Gg N for Quebec in the growing season. In contrast, the Prairie provinces showed higher NO₃^- leaching in the growing season (23.1-37.4 Gg N) than in the non-growing season (10.4-13.7 Gg N). In summary, total fertilizer N increased the most over the 36 years in the Prairies which resulted in increased RSN and N leaching losses that will require further intervention.

[Phenotype-genotype analysis of the autosomal recessive hereditary hearing loss caused by OTOA variations]

Objective: To analyze the phenotypic-genotypic characteristics of hereditary deafness caused by OTOA gene variations. Methods: Family histories, clinical phenotypes and gene variations of six pedigrees were analyzed, which were diagnosed with hearing loss caused by OTOA gene variations at the PLA General Hospital from September 2015 to January 2022. The sequence variations were verified by Sanger sequencing and the copy number variations were validated by multiplex ligation-dependent probe amplification (MLPA) in the family members. Results: The hearing loss phenotype caused by OTOA variations ranged from mild to moderate in the low frequencies, and from moderate to severe in the high frequencies in the probands, which came from six sporadic pedigrees, among which a proband was diagnosed as congenital deafness and five were diagnosed as postlingual deafness. One proband carried homozygous variations and five probands carried compound heterozygous variations in OTOA gene. Nine pathogenic variations (six copy number variations, two deletion variations and one missense variation) and two variations with uncertain significance in OTOA were identified in total, including six copy number variations and five single nucleotide variants, and three of the five single nucleotide variants were firstly reported [c.1265G>T(p.Gly422Val),c.1534delG(p.Ala513Leufs*11) and c.3292C>T(p.Gln1098fs*)]. Conclusions: OTOA gene variations can lead to autosomal recessive nonsyndromic hearing loss. In this study, the hearing loss caused by OTOA defects mostly presents as bilateral, symmetrical, and postlingual, and that of a few presents as congenital. The pathogenic variations of OTOA gene are mainly copy number variations followed by deletion variations and missense variations.

[Phenotypic and genotypic characteristics of Escherichia coli causing bloodstream and abdominal co-infection]

Objective: To analyze the phenotypic and genotypic characteristics of Escherichia coli causing bloodstream and abdominal co-infection (CoECO), and provide clues for empirical antibiotics treatment. Methods: The strains of Escherichia coli isolated from blood and abdominal samples in the Department of Laboratory Medicine of the First Medical Center of the PLA General Hospital from 2010 to 2020 were retrospectively analyzed. Mass spectrometer was used to identify all of the strains and the minimum inhibitory concentration (MIC) were detected by VITEK 2 Compact. All isolates were sequenced by 2×150 bp double terminal sequencing strategy on the HiSeq X Ten sequencer (Illumina). After the genome sequence was spliced, the single nucleotide polymorphism (SNP) analysis of the strain sequence was performed using kSNP3 software to clarify the homologous relationship between strains. If the strains isolated from two different parts had high homology, they were regarded as the same strain and the case was with CoECO infection. Meanwhile, the multilocus sequence type (MLST) was determined using PubMLST website and resistant genes were screened by CARD website. Results: A total of 70 cases of CoECO infection were screened, including 45 males and 25 females, and aged (59.2±16.3) years old. The 70 CoECO isolates belonged to 35 sequence types (STs). The most prevalent STs included ST38 (n=6), ST 405 (n=6), ST 1193 (n=6) and ST131 (n=5), and other ST types contained less than 5 strains. The homologous relationship among strains was relatively scattered, presenting a sporadic trend as a whole, and only a few strains had a small-scale outbreak. The CoECO isolates showed significantly resistance to ampicillin (91.4%, 64/70), ampicillin/sulbactam (74.3%, 5 2/70), ceftriaxone (72.9%, 51/70), ciprofloxacin (71.4%, 50/70) and levofloxacin (71.4%, 50/70), and high-sensitivity to piperacillin/tazobactam, carbapenems and amikacin. The most prevalent resistant gene was tet (A/B) (70%, 49/70), followed by bla_TEM (58.6%, 41/70), sul1 (55.7%, 40/70), sul2 (54.3%, 38/70), bla_CTX-M-14(25.7%, 18/70), bla_CTX-M-15(17.1%, 13/70), bla_CTX-M-55(15.7%, 11/70), bla_CTX-M-64/65(5.7%, 4/70), bla_CTX-M-27(4.3%, 3/70), mcr-1 (4.3%, 3/70), bla_NDM-5(2.9%, 2/70). Conclusions: CoECO is distributed dispersedly and has no obvious advantage clone. No genotype with obvious advantages was found. Although the strain has a high resistance rate to some antibacterial drugs, the proportion of carrying resistant genes is low, and it has a high sensitivity to some first-line antibacterial drugs.

[Attention should be paid to the lifelong monitoring of diabetic retinopathy in people with diabetes]

Diabetic retinopathy (DR) is one of the severe complications of diabetes, and also the most common reason of vision loss in Chinese adults over 30 years old. Regular fundus examination and continuous glucose monitoring can prevent 98% of blindness caused by DR. However, due to the irrational allocation of medical resources and the weak awareness of DR patients, only about 50% to 60% of diabetes patients have an annual DR screening. Therefore, it is necessary to build a follow-up system for early screening, prevention, treatment and lifelong monitoring of DR patients. In this review, we discuss the importance of lifelong monitoring, the hierarchical medical system and the follow-up of pediatric DR patients. Novel and multi-level screening methods are cost-saving to patients and cost-effective to healthcare systems, and also can help improve the detection and early treatment of DR.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

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.

[Analysis of clinical prognosis of endoscopic salvage surgery in patients with rT2 recurrent nasopharyngeal carcinoma]

Objective: To investigate the feasibility of endoscopic salvage surgery for patients with rT2 recurrent nasopharyngeal carcinoma (rNPC) and to analyze their prognostic factors. Methods: The clinical data of 33 patients with rT2 rNPC who underwent endoscopic extended nasopharyngectomy in Eye & ENT Hospital Affiliated to Fudan University from January 2015 to July 2020 were analyzed, including 29 males (87.9%) and 4 females (12.1%), aging (51.7±10.6) years. The clinicopathological characteristics of these patients were recorded and analyzed, in terms of gender, sex, alcohol and cigarette use, interval between primary treatment to recurrence, adjuvant therapy, lymph node metastasis, internal carotid artery (ICA) invasion, necrosis, margin and reconstruction materials. Kaplan Meier analysis was used to plot the overall survival rate and progression free survival rate curve, Log-rank test was used to analyze the prognostic factors among patients, and multivariate Cox proportional hazards regression was used to determine the independent risk factors of tumor progression free survival. Results: Among 33 patients with rT2 rNPC, the recurrence interval of 24 patients with rNPC after primary radiotherapy was more than 2 years. A total of 25 patients received primary radiotherapy and adjuvant chemotherapy at the same time. There were 6 cases with cervical lymph node metastasis, 12 cases with ICA invasion, 8 cases with positive surgical margin, 7 cases underwent ICA embolization before operation. A total of 18 cases underwent pedicled tissue flap repairment after operation, including 12 pedicled nasal septal mucosa flaps and 6 temporalis muscle flaps. The median follow-up time was 15 months. Five patients died because of disease progression (in 2 cases), post surgical ICA hemorrhage (in 1 case), liver metastasis (in 1 case) and dysphagia (in 1 case). The 1-year, 2-year and 3-year overall survival rates of all patients were 93.9%, 81.8% and 81.8%, respectively. The 1-year, 2-year and 3-year progression free survival rates were 74.7%, 59.7% and 40.9%, respectively. Log-rank statistical analysis showed that the positive surgical margin (P=0.060) and recurrence interval (P=0.151) were possibly related to the prognosis of rT2 rNPC. Multivariate Cox regression analysis showed that the positive surgical margin was an independent risk factor for patients with rT2 rNPC (P=0.034). Nasopharynx hemorrhage occurred in 4 patients, skull base bone necrosis occurred in 2 patients, trismus occurred in 3 patients, and no obvious brain complications occurred in 7 patients with ICA embolization. Conclusion: Endoscopic salvage surgery for rT2 rNPC is a safe and effective surgical option, but the long-term effect still needs long-term follow-up in bulk cases.

Prx1 Regulates Thapsigargin-Mediated UPR Activation and Apoptosis

Endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR) signaling via the accumulation of unfolded and misfolded proteins. ER stress leads to the production of reactive oxygen species (ROS), which are necessary to maintain redox homeostasis in the ER. Although peroxiredoxin 1 (Prx1) is an antioxidant enzyme that regulates intracellular ROS levels, the link between Prx1 and ER stress remains unclear. In this study, we investigated the role of Prx1 in X-box binding protein 1 (XBP-1) activation, the C/EBP homologous protein (CHOP) pathway, and apoptosis in response to ER stress. We observed that Prx1 overexpression inhibited the nuclear localization of XBP-1 and the expression of XBP-1 target genes and CHOP after thapsigargin (Tg) treatment to induce ER stress. In addition, Prx1 inhibited apoptosis and ROS production during ER stress. The ROS scavenger inhibited ER stress-induced apoptosis but did not affect XBP-1 activation and CHOP expression. Therefore, the biological role of Prx1 in ER stress may have important implications for ER stress-related diseases.

Short and long-term inequity in outpatient medical use by the type of medical institutions in Korea

Background

Many countries agree with the horizontal equity that medical resources should be allocated according to medical needs, regardless of income. Although the short-term equity index calculated through cross-sectional data doesn't reflect the dynamics of individual income and medical use, it can be supplemented by the long-term equity index using panel data. Koreans tend to choose expensive but highly specialized services without considering their medical needs because they are free to choose service providers. This study aims to empirically examine how the patterns of outpatient medical use that are not based on medical needs differ in terms of short- and long-term equity for each type of medical institution.

Methods

Using Korea Health Panel Survey(2014-2018), the equity of outpatient medical use(number of visits, medical expenses) of 10,244 people was measured by type of medical institution (tertiary general hospital, general hospital, hospital, clinic, and dentist). Wagstaff&van Doorslaer(2000)’s tool and Jones & Lopez-Nicolas(2004)’s tool were used to calculate the short and long-term horizontal equity index(HI), and mobility index(MI) to compare short and long-term inequity.

Results

In tertiary general hospitals and dentists, there were short and long-term pro-rich inequalities(HI &gt; 0, p &lt; 0.05). As a result of comparison, long-term inequality was greater in the number of visits (MI &lt; 0), while inequality was easing in the long-term in medical expenses(MI &gt; 0) in tertiary general hospitals. In dentists, long-term inequality was less than short-term inequality in both the number of visits and medical expenses (MI &gt; 0).

Conclusions

The short-term equity index is likely to underestimate or overestimate inequity in our society, so a long-term perspective is needed. Inequality patterns for each type of medical institution should be considered in healthcare reforms for fair distribution of medical resources.

Key messages

• Short-term equity index differs from the long-term equity index in outpatient medical use.

• The pattern of short and long-term equity indices may differ by type of medical institutions.

[Research progress on infiltrating zone and microvascular invasion of hepatic alveolar echinococcosis]

Hepatic alveolar echinococcosis (AE) is a parasitic disease with biological characteristics similar to malignant tumor. It has no obvious clinical symptoms in the early stage. Most patients have complications such as jaundice, ascites and gastrointestinal bleeding when they see a doctor. At this time, the course of disease is at an advanced stage. In addition, the incomplete resection of the AE lesion(s) leads to a high postoperative recurrence rate, which has a serious impact on the physical and mental health of patients. Based on the summary of the latest research at home and abroad and the analysis of blood supply, microvascular invasion and vascular growth factor expression in the "infiltrating zone" adjacent to the lesions of hepatic AE, this article has a deep understanding of the occurrence and development process of hepatic AE, aiming to better guide clinical practice and improve the quality of life of patients.

[Design of non-metallic crown for primary molars and analyzation of stress distribution: a finite element study]

Objectives: To study the design of nonmetallic crowns for deciduous molars by means of computer aided design and to analyze the key parameters of the nonmetallic crowns of deciduous molars using finite element method. Methods: The three-dimensional model of a mandibular second primary molar was constructed by using a micro-CT system. The thickness of the crown was limited to 0.5 mm and four different crown shapes (chamfer+anatomic, chamfer+non-anatomic, knife edge+anatomic and knife edge+non-anatomic) were designed. Then, the crown shape was limited as chamfer+non-anatomic and five different thicknesses of the crown (0.50, 0.75, 1.00, 1.25, 1.50 mm) were designed, and three different materials, including polyetherketoneketone (PEKK), polymethylmethacrylate (PMMA) resin and resin-infiltrated ceramic, were applied to make the crown. Stress distribution and fatigue of each component of the model under vertical and oblique loadings were analyzed by using finite element method. Non-axial retention analysis was performed on chamfer+non-anatomic crowns, made of PMMA resin, with thicknesses of 0.50, 0.75, 1.00, 1.25 and 1.50 mm. Results: Among the four crown shape designs, the chamfer+non-anatomic type crown showed the lowest von Mises stress and the highest safety factor. By comparing three different materials, the resin-infiltrated ceramic group showed obvious stress concentration on the buccal edge of the crown and the PEKK group showed stress concentration in the adhesive layer. Results of non-axial retention analysis showed that the torques required by the crowns with five thicknesses at the same rotation angle were as follows: 4 856.1, 4 038.1, 3 497.3, 3 256.3 and 3 074.3 N⋅m, respectively. The comparison of areas of the adhesives fracture among groups were as follows: 0.5 mm group < 0.75 mm group < 1.00 mm group < 1.25 mm group < 1.50 mm group. Conclusions: In the design of nonmetallic crowns for primary molars, the edge of the crown should be designed as chamfer, the shape of the inner crown should be non-anatomical and the minimum preparation amount of the occlusal surface should be 1.00 mm. Among the three materials, PMMA resin, of which elastic modulus is similar to the dentin and the dental adhesive, might be the most suitable material for the crowns of primary molars.

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.

Nipple Reconstruction Using the Semilunar Flap and Omega-shaped Acellular Dermal Matrix Strut

BACKGROUND

Various operative methods exist for nipple reconstruction. Selection of an appropriate skin flap and core strut material is imperative in achieving a satisfactory outcome in nipple reconstruction. Long-term maintenance of nipple projection requires further investigation by surgeons. We propose a new technique that uses a semilunar flap and omega-shaped acellular dermal matrix (ADM).

METHODS

Total 53 nipples were reconstructed by this method. An omega-shaped ADM strut was inserted into the barrel made by a semilunar flap. The footplates of omega-shaped ADM struts were spread out under the subcutaneous tissue of the donor site of the semilunar flap to support the dome of the omega strut.

RESULTS

The mean maintenance rate of nipple projection was 95.12 ± 6.30% at 3 weeks, 80.60 ± 8.93% at 3 months, and 71.70 ± 8.67% at 6 months postoperatively when compared to the projection observed in the immediate postoperative period. Thirty-five patients (66.0%) showed a maintenance rate over 70% at 6 months post operation, with most patients (94.3%) demonstrating a maintenance rate greater than 60%.

CONCLUSIONS

Our study with the omega-shaped ADM strut showed superior maintenance rates of projection when compared to other studies on that used AlloDerm^® as a core strut for nipple reconstruction. Omega-shaped struts, when made with cross-linked thick ADM, supported the skin flap quite well. We propose that our method combining the semilunar flap with an omega-shaped ADM may be a good option for nipple reconstruction. 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 ."

Prevention of Breast Implant Displacement Using the Acellular Dermal Matrix Garter Belt

BACKGROUND

Since the issue of breast implant-associated anaplastic large cell lymphoma, smooth breast implants tend to be the more preferred option in implant-based breast reconstructions, compared to its use previously. The most unfavorable aspect of smooth implants is lateral and inferior displacements, which are more common in patients who undergo breast reconstruction compared to augmentation mammoplasty. Hence, we introduce a prevention method for implant displacement using an acellular dermal matrix garter belt.

METHODS

This study is a retrospective review of patients who had undergone implant-based breast reconstruction between April 2019 and December 2020. Some patients who have highly possibility of implant displacement, had undergone the application of an ADM garter belt to prevent lateral or superior displacement. Implant displacement was assessed before and at least 6 months postoperatively.

RESULTS

A total of 155 IBR cases were recorded. ADM garter belts were applied in 27 patients (17.4%) who had a high tendency of implant displacement for several reasons, which could be classified into two categories: wide breast pocket (56%) and tight inferomedial breast pocket (44%). The intraoperative average distance of lateral slipping on patients' reconstructed breasts from the chest wall midline in supine position was 3.02 ± 0.81 cm and corrected to1.54 ± 0.69 cm at least 6 months postoperative follow-up.

CONCLUSIONS

We utilized an ADM strap as an internalized garter belt to minimize implant displacement. This ADM garter belt combined with capsuloplasty might be an effective way to prevent the displacement of smooth implants in the patients with a greater risk of implant displacement.

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.

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.

Assessing the impacts of diversified crop rotation systems on yields and nitrous oxide emissions in Canada using the DNDC model

Process-based models are effective tools for assessing the sustainability of agricultural productivity and environmental health under various management practices and rotation systems. The objectives of this study were to (1) calibrate and evaluate the DeNitrification-DeComposition (DNDC) model using measurements of yields, nitrogen (N) uptake, soil inorganic N, soil temperature, soil moisture and nitrous oxide (N₂O) emissions under long-term fertilized continuous corn (CC) and corn-oats-alfalfa-alfalfa (COAA) rotation systems in southwest Ontario from 1959 to 2015, Canada, and (2) explore the impacts of four diverse rotation systems (CC, COAA, corn-soybean-corn-soybean (CSCS) and corn-soybean-winter wheat (CSW)) on corn yields and annual N₂O emissions under long-term climate variability. DNDC demonstrated "good" performance in simulating corn, oats and alfalfa yield (normalized root mean square error (nRMSE) < 20%, Nash-Sutcliffe efficiency (NSE) > 0.5 and index of agreement (d) > 0.8). The model provided "fair" to "good" simulations for corn N uptake and soil inorganic N (NSE > 0.2 and d > 0.8), and also daily soil temperature and soil moisture (nRMSE <30% and d > 0.7) for both calibration and validation periods. The model demonstrated "good" performance in estimating daily and cumulative N₂O emissions from both the continuous and rotational corn, whereas it produced "poor" to "good" predictions for N₂O emissions from the rotational oats and alfalfa crops, however, the emissions from these crops were very low and the relative magnitude of these emissions between all crops investigated were well predicted. The lowest N₂O emissions were from COAA followed by CSCS, CSW then CC. The highest corn yields were from COAA, followed by CSW, CSCS, then CC. This study highlights how modelling approaches can help improve the understanding of the impacts of diversified rotations on crop production and greenhouse gas emissions and contribute towards developing policies aimed at improving the sustainability and resiliency of cropping systems.

[The involvement of neuropilin-1 in primary immune thrombocytopenia]

Objective: To explore the relationship between the expression of neuropilin-1 (NRP-1) on Treg cells and its ligands semaphorins-3A (Sema3A) , transforming growth factor-β(1) (TGF-β(1)) as well as the balance of type 1 helper T cells (Th(1)) and type 2 helper T cells (Th(2)) cells. Methods: This study enrolled 62 patients with immune thrombocytopenia (ITP; 33 and 29 newly diagnosed and chronic ITP, respectively) from March 2014 to May 2015. Consequently, 30 healthy people in the same period were selected as the normal control group. The expression of NRP-1 in Treg cells was detected via flow cytometry. The Sema3A, TGF-β(1), IFN-γ, and IL-4 levels in plasma were detected by enzyme-linked immunosorbent assay. The real-time polymerase chain reaction technique was used to detect the mRNA expression levels of NRP-1, Sema3A, and TGF-β(1). The one-way analysis of variance and independent sample t-test was used for comparison between three and two groups, respectively. Correlations among the mRNA expression levels of NRP-1, Sema3A, and TGF-β(1) were assessed via Spearman correlation coefficients. Results: Treg cells in the newly diagnosed ITP group significantly increased compared with those in the chronic ITP and normal control groups. The expression of NRP-1 decreased[ (0.15 ± 0.03) %, (0.33 ± 0.15) %, and (0.46 ± 0.06) %; P<0.01], the plasma Sema3A level increased[ (8.10 ± 1.32) μg/L, (7.41±1.30) μg/L, and (2.88±0.82) μg/L; P<0.01], and the plasma TGF-β(1) level decreased[ (16.50±3.36) μg/L, (35.17±10.26) μg/L, and (41.00±10.02) μg/L; P<0.01]. Moreover, the level of plasma IFN-γ increased[ (17.21+2.80) ng/L, (10.23+1.59) ng/L, and (8.18+3.27) ng/L; P<0.01], and the ratios of Th(1)/Th(2) (IFN-γ/IL-4) increased (1.29±0.30, 0.72±0.16, and 0.61±0.27; P<0.01) . The mRNA expressions of NRP-1 and Sema3A in the newly diagnosed ITP and chronic ITP groups were lower than that in the normal control group (P<0.01) . Consequently, the NRP-1 mRNA expression was positively correlated with Sema3A and TGF-β(1) mRNA expression in the newly diagnosed ITP group. Conclusion: NRP-1 played an essential role in the pathogenesis of ITP.

[Veracity of using a visual chart with a testing distance of 2.5 meters for measurement of distance visual acuity in teenagers]

Objective: To compare the results of visual acuity testing for teenagers with visual acuity charts designed at 2.5-meter and 5-meter distances, and to investigate the accuracy of the 2.5-meter visual acuity chart. Methods: It was a self-control study. A total of 227 teenagers (454 eyes) with ametropia who came to the ophthalmic clinic of Peking Union Medical College Hospital from March 2019 to September 2019 were included. There were 123 males and 104 females aged (11.74±3.26) years. The vision examiners were trained in the same testing environment and passed the consistency test. Distance visual acuity of all participants was tested with charts designed at 2.5 meters and 5 meters in a 10-minute interval. According to the age (7-9, 10-12, 13-15 and 16-18 years old) and visual acuity (1.00-0.52, 0.40-0.30 and 0.22-0.10), the results of two kinds of visual acuity charts were compared. The testing order of the two visual charts was randomly determined. The visual acuity results were converted into logMAR values and compared. Paried t-student test was used to compare the difference between two charts, and Pearson correlation test was used to explore the correlation between the results of two charts. Results: The visual acuity of the right eye was 0.37±0.24 (logMAR) at 2.5 meters and 0.50±0.26 (logMAR) at 5 meters. The distance visual acuity measured with the 2.5-meter visual acuity chart was better (t=16.19, P<0.01). The visual acuity of the left eye was 0.36±0.23 (logMAR) at 2.5 meters and 0.45±0.23 (logMAR) at 5 meters (t=11.71, P<0.01). The differences between two charts were larger among teenagers with lower visual acuity (r=0.387,P<0.01). Conclusion: Under the same test conditions, the distance visual acuity measured with a 2.5-meter chart was significantly better than a 5-meter chart. The visual acuity chart designed at 2.5 meters was not an appropriate tool to measure distance vision in adolescents. (Chin J Ophthalmol, 2021, 57: 122-125).