[Clinical effects of free peroneal artery perforator flaps in repairing forefoot skin and soft tissue defect wounds assisted with three-dimensional computed tomography angiography]

Objective: To investigate the clinical effects of free peroneal artery perforator flaps in repairing forefoot skin and soft tissue defect wounds assisted with three-dimensional computed tomography angiography (3D-CTA). Methods: A retrospective observational study was conducted. From March 2017 to September 2019, 15 patients with skin and soft tissue defect wounds in the forefoot were treated in the Department of Burn and Plastic Surgery of Yidu Central Hospital of Weifang, including 12 males and 3 females, with age of 18-60 years. The wound area on admission was 3.0 cm×3.0 cm-9.0 cm×8.0 cm. The 3D-CTA examination before operation was performed to select the peroneal artery perforating vessels with appropriate length of vascular pedicle and good blood perfusion. According to the wound area and the perforating vessels of the peroneal artery located by 3D-CTA, the peroneal artery perforator flaps of 3.5 cm×3.5 cm-9.5 cm×8.5 cm carried with lateral sural cutaneous nerve was designed and cut, and the nerve was anastomosed with the nerve of the wound. The wound in the donor site of the flap was directly sutured or covered with medium-thickness skin graft from the thigh. The consistencies of type, diameter, and perforating position of perforating vessel of the peroneal artery detected by 3D-CTA before the operation with those of the actual measurement during operation were observed. The length of time for flap cutting and the survival of the flap after operation were recorded. During follow-up of 12 months after the operation, the patients were instructed to evaluate the foot function according to the Maryland foot function score standard, and the wound healing in the donor area and the occurrence of complications affecting the motor function of limb were observed. Data were statistically analyzed with paired sample t test. Results: The types of peroneal artery perforating vessels in patients measured during the operation were septocutaneous perforator of 12 cases, musculocutaneous perforator of 2 cases, and musculomuscular septal perforator of 1 case, which were consistent with those measured by preoperative 3D-CTA. The diameter of the peroneal artery perforating vessel measured by preoperative 3D-CTA was (1.38±0.17) mm, which was close to (1.40±0.19) mm measured during the operation (t=0.30, P>0.05). The horizontal distance from the starting point of the perforating vessel to the outer edge of the shank was (42±6) mm, and the vertical distance from the starting point of the perforating vessel to the level of the lateral ankle tip was (219±14) mm measured by preoperative 3D-CTA, which were respectively close to (43±6) and (221±15) mm of intraoperative measurement (with t values of 0.46 and 0.38, respectively, P>0.05). The length of time for cutting flap was (31±6) min. All flaps survived post operation without vascular crisis. During follow-up of 12 months after the operation, the foot function was evaluated as excellent in 11 cases, good in 3 cases, and fair in 1 case, the donor site wound healed well, the scar was not noticeable with no contracture, and the motor function of joints was not affected. Conclusions: Free peroneal artery perforator flap is one of the effective methods to reconstruct skin and soft tissue defect wounds in the forefoot, and the risk of surgery can be reduced when the anatomical location of the perforating vessels is confirmed by 3D-CTA.

Chemical synthesis, biological activities, and molecular simulations of novel sulfonylurea compounds bearing ortho-alkoxy substitutions

A series of 51 novel sulfonylurea compounds with ortho-alkoxy substituent at phenyl ring were chemically synthesized and spectroscopically characterized. The biological activities of the target compounds were evaluated using the enzyme inhibition against acetohydroxyacid synthase (AHAS; EC 2.2.1.6) from fungal or plant source, as well as cell-based antifungal assay and greenhouse pot herbicidal assay. Among the target compounds, 6e showed desirable antifungal activity against Candida albicans standard isolate sc5314 with minimum inhibition concentration (MIC) of 0.39 mg/L (0.98 μM) after 24 h, and 6a demonstrated promising pre-emergence herbicidal activity against Echinochloacrus-galli at 30 g/ha dosage. Representative compounds 6a, 6e, and 6i showed no cell cytotoxicity even at 40 mg/L concentration. Theoretical DFT calculations indicated HOMO maps should be considered to understand the structure-activity relationships. The present study has hence provided useful information for further discovery of novel antifungal agents or selective herbicides.

Probing ^{93m}Mo Isomer Depletion with an Isomer Beam

The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

First report of Cladosporium tenuissimum causing leaf spot of Arachis hypogaea in China

Peanut (Arachis hypogaea L.), one of the most important oilseed crops in tropical and subtropical regions of the world (Kumar and Kirti 2011), is widely cultivated for its high protein and oil content in seeds. In August 2019, about 30% of A. hypogaea plants were found infected by leaf spot in the peanut-growing regions of Shandong Province, China. Disease symptoms appeared as the irregular and brown necrotic lesions on leaves that were 0.5 to 5.0 mm in diam. Twenty symptomatic plants were randomly sampled from peanut planting areas in Weihai and Yantai City. Small pieces (3 mm2) were cut from lesions, dipped in a 0.5% NaClO for 10 min, rinsed three times with sterilized distilled water, dried, placed onto potato-dextrose agar (PDA), and incubated in the dark at 25°C for 10 days. Three typical Cladosporium-like strains were isolated from diseased leaves of peanut. The colonies were grey to olivaceous green, reverse olivaceous black and woolly. The conidiophores were solitary, macronematous, unbranched or branched, straight or flexuous, cylindrical, slightly swollen at the apex, smooth. Conidiogenous cells were integrated, terminal and intercalary, with numerous loci on nodulose swelling. Ramoconidia were cylindrical, oblong, fusiform, 8.0 to 19.5×2.0 to 4.5 µm, aseptate or 1 septum, pale brown. Conidia were catenate, in densely branched chains, ellipsoid, ovoid, limoniform, aseptate, 4.0 to 11.5×2.5 to 5.5 µm, smooth, with conspicuous hila. The conidia easily break off from the chains. The morphological characteristics of these isolates matched the descriptions of Cladosporium tenuissimum (Bensch et al. 2010). For the molecular identification, the partial actin (act) and translation elongation factor 1-alpha (tef1) genes were amplified and sequenced using the respective primers ACT-512F/ACT-783R and EF1-728F/EF1-986R (Carbone and Kohn 1999). The representative sequences, deposited in GenBank (act: OL332701, OL332702 and OL332703; tef1: OL322090, OL322091 and OL322092), exhibited 99.6% and 100% identical to C. tenuissimum ex-type isolate CBS 125995 (HM148687 and HM148442). Phylogenetic analysis was done by Neighbor-Joining (NJ) analysis based on act+tef1 sequences. These three isolates were identified as C. tenuissimum by morphological and molecular characteristics. Pathogenicity of each C. tenuissimum isolate was tested on peanut in the greenhouse at 28°C with 75% relative humidity. Twenty plants of A. hypogaea were inoculated with the conidial suspension (1.0 × 105 conidia/ml) on the leaf surface. Ten plants were mock inoculated with sterile water as controls. Within 2 weeks, inoculated plants exhibited dark necrotic lesions on leaves which were similar to the symptoms observed in the field, while the mock inoculated plants remained symptomless. The fungal pathogen which was reisolated from inoculated rather than mock inoculated leaf tissues was identical to the original pathogen on the basis of morphological and molecular analysis, confirming Koch's postulates. To our knowledge, this is the first report of leaf spot caused by C. tenuissimum on peanut in China. The C. tenuissimum infection poses a serious threat by reducing the yield and quality of peanut in Shandong Province. This research is especially valuable to enhance epidemiological studies and implement effective control strategies.

Stochastic radiative transfer in random media. II. Coupling of radiation to material

We study the mechanism of the impact of random media on the stochastic radiation transport based on a one-dimensional (1D) planar model. To this end, we use a random sampling of mixtures combined with a deterministic solution of the time-dependent radiation transport equation coupled to a material temperature equation. Compared to purely absorbing cases [C.-Z. Gao et al., Phys. Rev. E 102, 022111 (2020)10.1103/PhysRevE.102.022111], we find that material temperatures can significantly suppress the impact of mixing distribution and size, which is understood from the analysis of energy transport channels. By developing a steady-state stochastic transport model, it is found that the mechanism of transmission of radiation is distance dependent, which is closely related to the mean free path of photons l_{p}. Furthermore, we suggest that it is the relationship between l_{p} and L (the width of random medium) that determines the impact of random media on the stochastic radiation transport, which is further corroborated by additional simulations. Most importantly, combining the proposed simple relationship and 1D simulations, we resolve the existing disputable issue of the impact of random media in previous multidimensional works, showing that multidimensional results are essentially consistent and the observed weak or remarkable impact of random media is mainly due to the distinctly different relationship between l_{p} and L. Our results may have practical implications in relevant experiments of stochastic radiative transfer.

Fractal microstructure effects on effective gas diffusivity of a nanoporous medium based on pore-scale numerical simulations with lattice Boltzmann method

The interaction between gas diffusion and complex microstructures of a nanoporous medium is important to gas diffusion in shale formation, but this interaction is complex and has not been fully understood. Those approaches based on fractal theory can well describe the fractal multiscale microstructure with simple boundaries. The lattice Boltzmann method (LBM) can consider the effects of complex microstructures at one scale. This study proposes a combination approach of fractal theory and LBM to simulate the gas diffusion process in fractal multiscale microstructures of a nanoporous medium. In this study, the gas diffusion in a complex microstructure at base scale is numerically simulated by the LBM and the gas diffusion in finer microstructures is described through a diffusion equation with a local gas diffusion coefficient. First, a microstructure of a nanoporous medium is reconstructed by a random reconstruction algorithm. Then, a local gas diffusion coefficient is proposed based on fractal theory to consider the effects of coupling molecular diffusion and Knudsen diffusion with the fractal structures of a nanoporous medium on the gas diffusion in finer microstructures. This local gas diffusion coefficient is validated by experimental data and introduced into the governing equation of gas diffusion. The LBM simulation is verified with experimental data and two other model results on the effective gas diffusivity of a nanoporous medium. Finally, key parameters for the effective gas diffusivity of a nanoporous medium are identified through sensitivity analysis. It is found that the effective gas diffusivity in a microstructure is higher for a smaller range of Knudsen number. Bigger pore diameter fractal dimension and smaller tortuosity fractal dimension represent lower gas diffusion resistance and have higher effective gas diffusivity. This combination approach provides a powerful tool to estimate the effective gas diffusivity in a complex nanoporous medium.

Sintering Rate and Mechanism of Supported Pt Nanoparticles by Multiscale Simulation

Thermal stability is the key issue in the industrial application of supported metal nanocatalysts. A combination method of density functional theory calculations, machine learning, and molecular dynamics simulation is adopted to study the sintering behavior of supported platinum (Pt) nanoparticles on graphene or TiO₂ nanosheet, and analyze sintering mechanisms under different temperatures, particle sizes, and metal support interactions (MSIs). The results show that the agglomeration of supported nanoparticles is mainly based on the mechanism of small particle migration and growth. Small-sized particles with high surface energy determine the sintering rate. In addition, the increase of temperature is conducive to the agglomeration of particles, especially for systems with strong MSI. Based on the analysis of the sintering process, a sintering kinetic model of supported Pt nanoparticles related to particle size, temperature, and MSI is established, which provides theoretical guidance for the design of supported metal catalysts with high thermal stability.

Direct Measurement of the Astrophysical ^{19}F(p,αγ)^{16}O Reaction in the Deepest Operational Underground Laboratory

Fluorine is one of the most interesting elements in nuclear astrophysics, where the ^{19}F(p,α)^{16}O reaction is of crucial importance for Galactic ^{19}F abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the essential ^{19}F(p,αγ)^{16}O reaction channel. The γ-ray yields were measured over E_{c.m.}=72.4-344  keV, covering the Gamow window; our energy of 72.4 keV is unprecedentedly low, reported here for the first time. The experiment was performed under the extremely low cosmic-ray-induced background environment of the China JinPing Underground Laboratory, one of the deepest underground laboratories in the world. The present low-energy S factors deviate significantly from previous theoretical predictions, and the uncertainties are significantly reduced. The thermonuclear ^{19}F(p,αγ)^{16}O reaction rate has been determined directly at the relevant astrophysical energies.

[Methods and effects of high-frequency color Doppler ultrasound assisted reverse island flap of dorsal digital artery of ulnar thumb for repairing skin and soft tissue defects in the distal end of the same finger]

Objective: To explore the methods and effects of high-frequency color Doppler ultrasound assisted reverse island flap of dorsal digital artery of ulnar thumb for repairing skin and soft tissue defects in the distal end of the same finger. Methods: The retrospective cohort study method was applied. From March 2014 to January 2020, 43 patients with skin and soft tissue defects in the distal end of thumb were hospitalized in the Department of Hand and Foot Surgery of Yidu Central Hospital of Weifang, including 28 males and 15 females, aged 19-58 years. The time from injury to operation was 4 to 10 hours, and the area of wound defect was 1.5 cm×1.0 cm-5.0 cm×3.0 cm. The type and course of dorsal digital artery of ulnar thumb were detected by high-frequency color Doppler ultrasound before operation, based on which the reverse transfer of the island flap of dorsal digital artery of ulnar thumb was designed to repair the skin and soft tissue defects in the distal end of the same finger. The patients with absence of the dorsal digital artery of ulnar thumb were repaired by the greater fish reverse island flap pedicled with the radial palmar artery. The area of the flap was 2.0 cm×1.5 cm-5.5 cm×3.5 cm. The donor site wound was directly closed by suturing or covered with split-thickness skin graft from the inner side of the upper arm in the same arm. The status of dorsal digital artery of ulnar thumb detected by high frequency color Doppler ultrasound before operation was recorded. The type, course, and distribution of the dorsal digital artery of ulnar thumb detected before operation were compared with those observed during the operation. The survival of the flap was observed after operation. During the last follow-up, the appearance of the donor and recipient area of flaps was observed, the thumb function was evaluated with trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association, and the sensory function of the area transplanted with flap was evaluated with the sensory function evaluation standard. Results: The results of high-frequency color Doppler ultrasound showed that the dorsal digital artery of ulnar thumb was absent in 2 patients, while 41 patients had the dorsal digital artery of ulnar thumb, among which 20 cases were type 1 that started from the first dorsal metacarpal artery and ran on the surface of the first interosseous dorsal muscle; 16 cases were type 2 that started from the deep branch of the radial artery or the main artery of thumb and ran in the deep surface of the first interosseous dorsal muscle, including 10 cases of type 2a with the starting point in the basal region of the first metacarpal bone and 6 cases of type 2b with the starting point in the first metacarpal bone region; 5 cases were type 3 that started from the confluence of the first dorsal metacarpal artery and the main thumb artery in the region of the first metacarpophalangeal joint. The outer diameter of the vessel at the beginning of the dorsal digital artery of ulnar thumb was (1.12±0.31) mm, and the outer diameter of the vessel at the beginning of the accompany vein was (0.63±0.21) mm. The dorsal digital artery of ulnar thumb was concentrated in the ulnar side of the first metacarpophalangeal joint and snuff box region. The type, course, and distribution range of the dorsal digital artery of ulnar thumb observed during the operation were consistent with the results detected by high-frequency color Doppler ultrasound before operation. After the operation, the flaps survived in 43 patients. The patients were followed up for 6 months to 1 year. During the last follow-up, only linear scars were left in the donor area; there were no obvious pigmentation in the area transplanted with reverse island flap of dorsal digital artery of ulnar thumb, with good texture and elasticity, and beautiful appearance; the thumb function was evaluated as excellent in 23 cases, good in 17 cases, and fair in 3 cases; the sensory function of the area transplanted with flap was evaluated as S₄ level in 16 cases, S₃ level in 22 cases, and S₂ level in 5 cases. Conclusions: The reverse island flap of dorsal digital artery of ulnar thumb is one of the ideal methods to repair the skin and soft tissue defect in the distal end of the same finger, especially that beyond the distal interphalangeal joint. Preoperative detection with high-frequency color Doppler ultrasound can identify the type and distribution of dorsal digital artery of ulnar thumb, so as to design a personalized operation plan, resulting in good appearance of the donor and recipient area and thumb function after operation.

Discovery of ortho-Alkoxy Substituted Novel Sulfonylurea Compounds That Display Strong Herbicidal Activity against Monocotyledon Grasses

In the present study, we have designed and synthesized a series of 42 novel sulfonylurea compounds with ortho-alkoxy substitutions at the phenyl ring and evaluated their herbicidal activities. Some target compounds showed excellent herbicidal activity against monocotyledon weed species. When applied at 7.5 g ha^-1, 6-11 exhibited more potent herbicidal activity against barnyard grass (Echinochloa crus-galli) and crab grass (Digitaria sanguinalis) than commercial acetohydroxyacid synthase (AHAS; EC 2.2.1.6) inhibitors triasulfuron, penoxsulam, and nicosulfuron at both pre-emergence and postemergence conditions. 6-11 was safe for peanut for postemergence application at this ultralow dosage, suggesting that it could be considered a potential herbicide candidate for peanut fields. Although 6-11 and triasulfuron share similar chemical structures and have close K_i values for plant AHAS, a significant difference has been observed between their LUMO maps from DFT calculations, which might be a possible factor that leads to their different behaviors toward monocotyledon weed species.

[Evaluation of the effect of free fibular flap transplantation in repairing mandibular osteoradionecrosis defect in 151 cases]

Objective: To investigate the clinical effect of free fibula flap transplantation in repairing the defect of mandibular osteoradionecrosis (ORN). Methods: A total of 151 mandibular ORN patients undergoing free fibular flap transplantation were selected from August 2005 to September 2020 in the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University. Among them, 109 patients were males and 42 patients were females, aged (54.1±10.1) (ranged 31-85) years old. The clinical data of the patients was collected and the survival rate of the flaps and postoperative function were calculated to evaluate the surgical efficacy. The χ² test was used for difference analysis. Results: Among the 151 patients, mandibular ORN caused by radiotherapy for nasopharyngeal carcinoma accounted for 79.5% (120/151). The average time for mandibular ORN appeared was 5(6) years after radiotherapy. Facial artery [57.2%(87/152)] and superior thyroid artery (50/152, 32.9%) were the main anastomotic arteries in the recipient area. There was no significant difference in the necrosis rates of the two flaps [10.3%(9/87) and 12.5%(5/50), respectively, P=0.949]. The main anastomotic veins in the recipient area were the external jugular vein [48.4%(135/279)] and the common facial vein [26.5%(74/279)]. Twenty-five cases (16.6%) had one vein anastomosed, and 126 cases (83.44%) had two veins anastomosed. There was no significant difference in the flap necrosis rate between the two conditions [20.0%(5/25) and 7.1%(9/126), respectively, P=0.100]. Ninety-seven cases (64.2%) used the peroneal musculocutaneous-fascia composite flap to repair the maxillofacial soft and hard tissue defects. Thirteen cases (8.6%) underwent the restorations with digital virtual surgery design, of which 5 cases were repaired with dental implants at the same time. After the operations, lower respiratory tract infection occurred in 17 patients (11.3%), and upper respiratory tract obstruction occurred in 3 cases (2.0%). The survival rate of the flap after operation was 90.7% (136/151), and 21 patients (13.9%) had flap vascular crisis. Delayed healing of maxillofacial wounds occurred in 33 cases (21.9%). After 3 to 24 months of follow-ups, 110 patients (76.9%) had no fistula inside/outside the oral cavity, 118 patients (82.5%) had an improvement in opening mouth of increasing (≥0.5 cm) after surgery, 135 patients (94.4%) had pain relief, 97 cases (67.8%) could eat normal diet, semi-liquid or soft food, and 137 cases (95.8%) were satisfied or basically satisfied with the treatment effects. Conclusions: The free fibular flap transplantation is an effective method to repair mandibular ORN defects. Preoperative vascular assessment is helpful for the selection of recipient vessels. Facial artery, superior thyroid artery, external jugular vein and common facial vein can be used as the main recipient vessels. The repair of the peroneal musculocutaneous-fascia composite flap facilitates the closure of internal and external fistulas. Digital technology can help to restore the maxillofacial shape more accurately, improve the patient's occlusal and chewing function and enhance the quality of life of mandibular ORN patients.

High-performance single-atom Ni catalyst loaded graphyne for H2O2 green synthesis in aqueous media

The electrochemical synthesis of hydrogen peroxide (H₂O₂) provides a greener and more efficient method compared with classic catalysts containing toxic metals. Herein, we used first-principles density functional theory (DFT) calculations to investigate 174 different single-atom catalysts with graphyne substrates, and conducted a three-step screening strategy to identify the optimal noble metal-free single atom catalyst. It is found that a single Ni atom loaded on γ-graphyne with carbon vacancies (Ni@V-γ-GY) displayed remarkable thermodynamic stability, excellent selectivity, and high activity with an ultralow overpotential of 0.03 V. Furthermore, based on ab-initio molecular dynamic and DFT calculations under the H₂O solvent, it was revealed that the catalytic performance for H₂O₂ synthesis in aqueous phase was much better than that in gas phase condition, shedding light on the hydrogen bond network being beneficial to accelerate the transfer of protons for H₂O₂ synthesis.

New α-Emitting Isotope ^{214}U and Abnormal Enhancement of α-Particle Clustering in Lightest Uranium Isotopes

A new α-emitting isotope ^{214}U, produced by the fusion-evaporation reaction ^{182}W(^{36}Ar,4n)^{214}U, was identified by employing the gas-filled recoil separator SHANS and the recoil-α correlation technique. More precise α-decay properties of even-even nuclei ^{216,218}U were also measured in the reactions of ^{40}Ar, ^{40}Ca beams with ^{180,182,184}W targets. By combining the experimental data, improved α-decay reduced widths δ^{2} for the even-even Po-Pu nuclei in the vicinity of the magic neutron number N=126 are deduced. Their systematic trends are discussed in terms of the N_{p}N_{n} scheme in order to study the influence of proton-neutron interaction on α decay in this region of nuclei. It is strikingly found that the reduced widths of ^{214,216}U are significantly enhanced by a factor of two as compared with the N_{p}N_{n} systematics for the 84≤Z≤90 and N<126 even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the π1f_{7/2} and ν1f_{5/2} spin-orbit partner orbits, which is supported by the large-scale shell model calculation.

[Establishment and validation of a predictive nomogram model for advanced gastric cancer with perineural invasion]

Objective: Peripheral nerve invasion (PNI) is associated with local recurrence and poor prognosis in patients with advanced gastric cancer. A risk-assessment model based on preoperative indicators for predicting PNI of gastric cancer may help to formulate a more reasonable and accurate individualized diagnosis and treatment plan. Methods: Inclusion criteria: (1) electronic gastroscopy and enhanced CT examination of the upper abdomen were performed before surgery; (2) radical gastric cancer surgery (D2 lymph node dissection, R0 resection) was performed; (3) no distant metastasis was confirmed before and during operation; (4) postoperative pathology showed an advanced gastric cancer (T2-4aN0-3M0), and the clinical data was complete. Those who had other malignant tumors at the same time or in the past, and received neoadjuvant radiochemotherapy or immunotherapy before surgery were excluded. In this retrospective case-control study, 550 patients with advanced gastric cancer who underwent curative gastrectomy between September 2017 and June 2019 were selected from the Affiliated Hospital of Qingdao University for modeling and internal verification, including 262 (47.6%) PNI positive and 288 (52.4%) PNI negative patients. According to the same standard, clinical data of 50 patients with advanced gastric cancer who underwent radical surgery from July to November 2019 in Qingdao Municipal Hospital were selected for external verification of the model. There were no statistically significant differences between the clinical data of internal verification and external verification (all P>0.05). Univariate analysis and multivariate logistic regression analysis were used to determine the independent risk factors for PNI in advanced gastric cancer, and the clinical indicators with statistically significant difference were used to establish a preoperative nomogram model through R software. The Bootstrap method was applied as internal verification to show the robustness of the model. The discrimination of the nomogram was determined by calculating the average consistency index (C-index). The calibration curve was used to evaluate the consistency of the predicted results with the actual results. The Hosmer-Lemeshow test was used to examine the goodness of fit of the discriminant model. During external verification, the corresponding C-index index was also calculated. The area under ROC curve (AUC) was used to evaluate the predictive ability of the nomogram in the internal verification and external verification groups. Results: A total of 550 patients were identified in this study, 262 (47.6%) of which had PNI. Multivariate logistic regression analysis revealed that carcinoembryonic antigen level ≥ 5 μg/L (OR=5.870, 95% CI: 3.281-10.502, P<0.001), tumor length ≥5 cm (OR=5.539,95% CI: 3.165-9.694, P<0.001), mixed Lauren classification (OR=2.611, 95%CI: 1.272-5.360, P=0.009), cT3 stage (OR=13.053, 95% CI: 5.612-30.361, P<0.001) and the presence of lymph node metastasis (OR=4.826, 95% CI: 2.729-8.533, P<0.001) were significant independent risk factors of PNI in advanced gastric cancer (all P<0.05). Based on these results, diffused Lauren classification and cT4 stage were included to establish a predictive nomogram model. CEA ≥ 5 μg/L was for 68 points, tumor length ≥ 5 cm was for 67 points, mixed Lauren classification was for 21 points, diffused Lauren classification was for 38 points, cT3 stage was for 75 points, cT4 stage was for 100 points, and lymph node metastasis was for 62 points. Adding the scores of all risk factors was total score, and the probability corresponding to the total score was the probability that the model predicted PNI in advanced gastric cancer before surgery. The internal verification result revealed that the AUC of nomogram was 0.935, which was superior than that of any single variable, such as CEA, Lauren classification, cT stage, tumor length and lymph node metastasis (AUC: 0.731, 0.595, 0.838, 0.757 and 0.802, respectively). The external verification result revealed the AUC of nomogram was 0.828. The C-ndex was 0.931 after internal verification. External verification showed a C-index of 0.828 from the model. The calibration curve showed that the predictive results were good in accordance with the actual results (P=0.415). Conclusion: A nomogram model constructed by CEA, tumor length, Lauren classification (mixed, diffuse), cT stage, and lymph node metastasis can predict the PNI of advanced gastric cancer before surgery.

Large Isospin Asymmetry in ^{22}Si/^{22}O Mirror Gamow-Teller Transitions Reveals the Halo Structure of ^{22}Al

β-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of β-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror β decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

[CD20-positive T cell lymphoma: clinicopathological features of five cases]

Objective: To investigate the clinicopathological characteristics of the T cell lymphomas with CD20 expression, and to better understand this rare entity. Methods: Two-hundred cases of T-cell lymphoma diagnosed in the Department of Pathology of the Affiliated Hospital of Qingdao University from November 2016 to February 2020 were examined, and 5 cases of CD20-positive T-cell lymphomas were identified and included. Combined with clinical data and review of the literature, the clinicopathological characteristics of the disease were analyzed. Results: The five patients were all male, and had an average age of 56 years (range, 47 to 64 years). There were 2 cases of monomorphic epitheliotropic intestinal T-cell lymphoma, 2 cases of mycosis fungoides (1 case was plaque stage and the other was tumor stage) and 1 case of indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. Immunohistochemistry showed that all 5 cases expressed multiple T cell markers (CD3/CD4/CD5/CD7/CD8) and only one of B cell markers (CD20). Three of the 5 cases were negative for CD20 at the first diagnosis, while CD20 was diffusely positive on the second biopsy from the recurrence or progression of the disease, without expression of CD79a or PAX5. Epstein-Barr encoding region (EBER) in situ hybridization was negative in all 5 cases. T-cell receptor gene analysis showed monoclonal rearrangement of β or/and δ chains;Ig rearrangements were all polyclonal. None of the five patients were treated with rituximab, and 4 patients survived with disease and 1 patient survived without disease at the end of follow-up. Among them, the patient with mycosis fungoides at the cancerous stage has progressed rapidly and had poor quality of life. Conclusions: CD20-positive T-cell lymphoma is extremely rare. Its prognosis is closely related to the type of T-cell lymphoma, clinical stage and initial therapeutic effect. However, the expression of CD20 indicates the recurrence or progression of the disease, and the prognosis is relatively poor. When CD3 expression is absent in T-cell lymphoma, it is easy to be misdiagnosed as B-cell lymphoma. The combination of multiple immunohistochemical antibodies and molecular detection can improve the accuracy of diagnosis.

Genomic and transcriptional heterogeneity of multifocal hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) often presents with multiple nodules within the liver, with limited effective interventions. The high genetic heterogeneity of HCC might be the major cause of treatment failure. We aimed to characterize genomic heterogeneity, infer clonal evolution, investigate RNA expression pattern and explore tumour immune microenvironment profile of multifocal HCC.

PATIENTS AND METHODS

Whole-exome sequencing and RNA sequencing were carried out in 34 tumours and 6 adjacent normal liver tissue samples from 6 multifocal HCC patients. Protein expression of Ki67, AFP, P53, Survivin and CD8 was detected by immunohistochemistry. Fluorescence in situ hybridization was carried out to validate the amplification status of sorafenib-targeted genes.

RESULTS

We deciphered genomic and transcriptional heterogeneity among tumours in each multifocal HCC patient including mutational profiles, copy number alterations, tumour evolutionary trajectory and tumour immune microenvironment profiles. Of note, sorafenib-targeted alterations were identified in the trunk of phylogenetic tree in only one out of the six patients, which may explain the relative low treatment response rate to sorafenib in clinical practice. Moreover, we demonstrated RNA expression patterns and tumour immune microenvironment profiles of all nodules. We found that RNA expression pattern was associated with Edmondson-Steiner grading. Based on the differential expression of 66 reported immune markers, unsupervised hierarchical clustering analysis of 34 nodules identified immune subsets: one low expression cluster with seven nodules and one high expression cluster with 11 nodules. CD8+ T cells were more enriched in nodules of the high expression cluster.

CONCLUSIONS

Our study provided a detailed view of genomic and transcriptional heterogeneity, clonal evolution and immune infiltration of multifocal HCC. The heterogeneity of druggable targets and immune landscape might help interpret the clinical responsiveness to targeted drugs and immunotherapy for multifocal HCC patients.

[Clinicopathological features and gene phenotypes of benign metastasizing leiomyoma]

Objective: To study the clinicopathological features, immunophenotypes and MED12 gene status in benign metastasizing leiomyoma (BML). Methods: Nine cases of BML diagnosed at the Affiliated Hospital of Qingdao University from 2012 to 2018 were collected, and the radiologic and histologic features were analyzed. The protein expression of leiomyosarcoma-related driver genes, including RB1, PTEN,ATRX,p16,p53, as well as ER,PR,CD34,FH, and Ki-67 were detected using immunohistochemistry, and the mutation status of MED12 gene exon 2 was detected by Sanger sequencing. Results: All the nine patients with BML were female, and the age range was 48 to 64 years (median 55 years). All patients had history of uterine fibroids. The morphologic features of BML were similar to a benign uterine leiomyoma and did not exhibit malignant characteristics. All cases were positive for ER and PR, and negative for CD34. In addition, RB1, PTEN, ATRX, and FH were positive in all cases (wild type), while p16 showed a focally positive pattern. P53 positive index was less than 5% (wild type), and Ki-67 positive index was less than 1%. Sanger sequencing was done in six BML samples; one sample harbored a nonsense mutation c. 142_144delinsTAA (p.Glu48Ter), and another exhibited a synonymy mutation (c.192C>T, p.Phe64=)and one missense mutation c.196C>T (p.Pro66Ser). Conclusions: The present study suggests that BML is a unique leiomyoma entity that is pathologically and genetically different from leiomyosarcomas and conventional uterine leiomyomas. Evaluating the genetic phenotype of BML, especially the expression of leiomyosarcoma-related driver genes protein and MED12 gene status, may be helpful in understanding the pathogenesis of BML and in its differentiation from leiomyosarcoma.

Heavy N+ ion transfer in doubly charged N2Ar van der Waals cluster

Van der Waals clusters are weakly bound atomic/molecular systems and are an important medium for understanding micro-environmental chemical phenomena in bio-systems. The presence of neighboring atoms may open channels otherwise forbidden in isolated atoms/molecules. In hydrogen-bond clusters, proton transfer plays a crucial role, which involves mass and charge migration over large distances within the cluster and results in its fragmentation. Here we report an exotic transfer channel involving a heavy N⁺ ion observed in a doubly charged cluster produced by 1 MeV Ne⁸⁺ ions: (N₂Ar)²⁺→N⁺+NAr⁺. The neighboring Ar atom decreases the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{N}}_2^{2 + }$$\end{document}N22+ barrier height and width, resulting in significant shorter lifetimes of the metastable molecular ion state \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{N}}_2^{2 + }$$\end{document}N22+(\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\mathrm{X}}^{1}}{\Sigma _{{\mathrm{g}}}^{+}}$$\end{document}X1Σg+). Consequently, the breakup of the covalent N⁺−N⁺ bond, the tunneling out of the N⁺ ion from the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{N}}_2^{2 + }$$\end{document}N22+ potential well, as well as the formation of an N−Ar⁺ bound system take place almost simultaneously, resulting in a Coulomb explosion of N⁺ and NAr⁺ ion pairs.

There are multiple ways by which energy and charge transfer occur in weakly bound systems. Here the authors reveal a heavy ion N⁺ transfer in a doubly charged Van der Waals cluster produced in collisions of the highly charged Ne⁸⁺ ion with N₂Ar, leading to fragmentation of N⁺ and NAr⁺ via Coulomb explosion.