Measured proton electromagnetic structure deviates from theoretical predictions

The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities¹ that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities² map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades². Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.

[Clinical characteristics of severe late-onset ovarian hyperstimulation syndrome and its impact on the live birth outcome of IVF-ET]

Objective: To investigate the correlation between different clinical features and live birth in patients with severe late-onset ovarian hyperstimulation syndrome (OHSS) after in vitro fertilization-embryo transfer (IVF-ET). Methods: The clinical information of 330 patients who were pregnant after IVF-ET and referred to medical treatments diagnosed as late-onset severe OHSS in Peking University Third Hospital from January 2016 to December 2020 was retrospectively analyzed. The patients were divided into live birth achieved group (n=287) and non-live birth achieved group (n=43) according to pregnancy outcomes, and live birth achieved group was further divided into two subgroups, full-term birth group (n=222) and early-term birth group (n=65) according to gestational week at delivery for better analysis. Single factor and multi-factor analysis were utilized to clarify the influencing factors of both live birth and early-term birth. Results: Among all the patients who received IVF-ET, the incidence of severe OHSS was 0.67% (673/100 758). Among 330 severe late-onset OHSS patients, 42.4% (140/330) had pleural effusion, the incidence of abnormal liver function was 69.4% (229/330), and the live birth rate was 87.0% (287/330). Among the 287 patients who achieved live birth, 55.4% (159/287) had no pleural effusion, 18.5% (53/287) had a small amount of pleural effusion, and 26.1% (75/287) had medium or massive pleural effusion; in the non-live birth achieved group, there were more patients without pleural effusion and less patients with a small amount of pleural effusion; the difference was statistically significant (χ²=6.213, P=0.045). The rate of selective fetal reduction in live birth achieved group was 16.0% (46/287), which was significantly higher than that in the non-live birth achieved group, which was 2.3% (1/43; χ²=5.749, P=0.017). Multivariate logistic regression analysis revealed that moderately abnormal liver function was an independent risk factor for live birth (OR=3.15, 95%CI: 1.60-6.19), while selective fetal reduction was an independent protective factor for live birth (OR=0.13, 95%CI: 0.02-0.96). Additionally, subgroup analysis suggested that twin birth was an independent risk factor for preterm birth (OR=8.54, 95%CI: 4.31-16.91). Conclusions: Moderate hepatic dysfunction may be associated with adverse pregnancy outcomes in patients with severe late-onset OHSS. Selective fetal reduction and singleton pregnancy are recommended to ameliorate live birth rate, full-term delivery rate, also the maternal and neonatal prognosis for patients with multiple pregnancies.

[Prenatal genetic diagnosis of the fetuses with isolated corpus callosum abnormality]

Objective: To explore the application value of chromosome karyotype analysis, chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in prenatal diagnosis of isolated corpus callosum abnormality (CCA) fetus. Methods: Fetuses diagnosed with isolated CCA by ultrasound and MRI and receiving invasive prenatal diagnosis in Guangzhou Women and Children's Medical Center and Qingyuan People's Hospital from January 2010 to April 2021 were selected. Karyotype analysis and/or CMA [or copy number variation sequencing (CNV-seq)] were performed on all fetal samples, and WES was performed on fetal samples and their parents whose karyotype analysis and/or CMA (or CNV-seq) results were not abnormal. Results: Among 65 fetuses with isolated CCA, 38 cases underwent karyotype analysis, and 3 cases were detected with abnormal karyotypes, with a detection rate of 8% (3/38). A total of 49 fetuses with isolated CCA underwent CMA (or CNV-seq) detection, and 6 cases of pathogenic CNV were detected, the detection rate was 12% (6/49). Among them, the karyotype analysis results were abnormal, and the detection rate of further CMA detection was 1/1. The karyotype results were normal, and the detection rate of further CMA (or CNV-seq) detection was 14% (3/21). The detection rate of CMA as the first-line detection technique was 7% (2/27). A total of 25 fetuses with isolated CCA with negative results of karyotyping and/or CMA were tested by WES, and 9 cases (36%, 9/25) were detected with pathogenic genes. The gradient genetic diagnosis of chromosomal karyotyping, CMA and WES resulted in a definite genetic diagnosis of 26% (17/65) of isolated CCA fetuses. Conclusions: Prenatal genetic diagnosis of isolated CCA fetuses is of great clinical significance. The detection rate of CMA is higher than that of traditional karyotyping. CMA detection could be used as a first-line detection technique for fetuses with isolated CCA. WES could increase the pathogenicity detection rate of fetuses with isolated CCA when karyotype analysis and/or CMA test results are negative.

GBP2 as a potential prognostic predictor with immune-related characteristics in glioma

Guanylate binding protein 2 (GBP2) is a member of the guanine binding protein family, and its relationship with prognostic outcomes and tumor immune microenvironments in glioma remains elusive. We found GBP2 were increased in glioma tissues at both mRNA and protein levels. Kaplan-Meier curves revealed that high GBP2 expression was linked with worse survival of glioma patients, and multivariate Cox regression analysis indicated that high GBP2 expression was an independent prognostic factor for glioma. Combined analysis in immune database revealed that the expression of GBP2 was significantly related to the level of immune infiltration and immunomodulators. Single-cell analysis illustrated the high expression of GBP2 in malignant glioma cells showed the high antigen presentation capability, which were confirmed by real-time polymerase chain reaction (qRT-PCR) data. Additionally, the hsa-mir-26b-5p and hsa-mir-335-5p were predicted as GBP2 regulators and were validated in U87 and U251 cells. Our results first decipher immune-related characteristics and noncoding regulators of GBP2 in glioma, which may provide insights into associated immunotherapies and prognostic predictor.

Permafrost degradation is accelerating beneath the bottom of Yanhu Lake in the Hoh Xil, Qinghai-Tibet Plateau

Lakes on the Qinghai-Tibet Plateau (QTP) have notably expanded over the past 20 years. Due to lake water level rise and lake area expansion, the permafrost surrounding these lakes is increasingly becoming submerged by lake water. However, the change process of submerged permafrost remains unclear, which is not conducive to further analyzing the environmental effects of permafrost change. Yanhu Lake, a tectonic lake on the QTP, has experienced significant expansion and water level rise. Field measurement results indicate that the water level of Yanhu Lake increased by 2.87 m per year on average from 2016 to 2019. Cold permafrost, developed in the lake basin, was partially submerged by lake water at the end of 2017. Based on the water level change and permafrost thermal regime, a numerical heat conduction permafrost model was employed to predict future changes in permafrost beneath the lake bottom. The simulated results indicate that the submerged permafrost would continuously degrade because of the significant thermal impact of lake water. By 2100, the maximum talik thicknesses could reach approximately 7, 12, 16, and 19 m under lake-bottom temperatures of +2.0, +4.0, +6.0, and +8.0 °C, respectively. Approximately 291 years would be required to completely melt 47 m of submerged permafrost under the lake-bottom temperature of +4 °C. Note that the permafrost table begins to melt earlier than does the permafrost base, and the decline in the permafrost table occurs relatively fast at first, but then the process is attenuated, after which the permafrost table again rapidly declines. Compared to climate warming, the degradation of the submerged permafrost beneath the lake bottom occurred more rapidly and notably.

[The influence of sacroiliac joint reduction quality on the clinical effect of bionic reduction and internal fixation for pelvic ring injury]

Objective: To examine the influence of sacroiliac joint reduction quality on the clinical effect of bionic reduction and internal fixation for pelvic ring injury. Methods: From January 2014 to February 2019,the clinical data of 78 patients diagnosed with pelvic ring injury involving sacroiliac joints and treated with bionic reduction and internal fixation at Honghui Hospital Affiliated to Medical College of Xi'an Jiaotong University were retrospectively analyzed.There were 48 males and 30 females,aged (48.3±8.3)years (range:28 to 68 years).After bionic reduction and internal fixation,the patients were grouped according to the maximum displacement distance (d) of sacroiliac joint residual on the damaged side measured by CT examination. Patients with d≤5 mm were included in anatomical bionic reduction group,and patients with d>5 mm were included in non-anatomical bionic reduction group.In non-anatomical bionic reduction group,according to the direction of residual displacement,the patients were divided into separation displacement group and anterior-posterior displacement group. The X-ray examination was performed immediately and at the last follow-up after operation.If sacroiliac joint was relocated,or internal plant loosening,displacement,fracture and re-displacement of fracture,it was defined as internal fixation failure.Majeed pelvic fracture scoring system was used to evaluate the postoperative functional status of the two groups,and visual analogue scale (VAS) was used to evaluate the postoperative pain.Comparison between groups was performed by completely random design ANOVA,χ² test,Fisher's exact test,Mann-Whitney U and Kruskal-Wallis H test. Results: According to the CT examination,28 cases were included in anatomical bionic reduction group,and 50 cases were included in non-anatomical bionic reduction group.In non-anatomical bionic reduction group,27 cases were divided into separation displacement group and 23 cases were in anterior-posterior displacement group.There was no significant difference in general data among anatomical bionic reduction group,separation displacement group and anterior-posterior displacement group (P>0.05). The follow-up time was (37.8±6.6) months (range:25 to 51 months). At the last follow up,the excellent and good rate of Majeed score in anatomical bionic reduction group was 96.4%(27/28),which was better than that in separation displacement group(74.1%(20/27)) and anterior-posterior displacement group (30.4%(7/23)),the difference was statistically significant (Z=-6.479,P<0.01;Z=-6.256,P<0.01); and the good rate of the separation displacement group was better than that of the anterior-posterior displacement group(Z=-3.607,P<0.01).The VAS of anatomical bionic reduction group (17 cases with 0 point, 11 cases with 1 to 3 points) were lower than that of the displacement group (6 cases with 0 point,16 cases with 1 to 3 points,5 cases with 4 to 6 points) and anterior-posterior displacement group (3 cases with 0 point,7 cases with 1 to 3 points,13 cases with 4 to 6 points),the difference was statistically significant (Z=-3.515,P<0.01;Z=-3.506,P<0.01),and there was no difference between separation displacement group and anterior-posterior displacement group.Total of 8 cases of internal fixation failure occurred,and the failure rate of anatomical bionic reduction group (0,0/28) was lower than that of the separation displacement group (11.1%,3/27) and anterior-posterior displacement group (21.7%,5/23) (P=0.111,P=0.014),and there was no difference between separation displacement group and anterior-posterior displacement group(P=0.444). Conclusions: In the bionic reduction and internal fixation of pelvic fracture involving sacroiliac joint injury,the functional status,pain and internal fixation failure rate of patients with anatomical bionic reduction of sacroiliac joint are significantly better than those in the non-anatomical bionic reduction.The functional recovery of patients with separation displacement is better than that of the patients with anterior and posterior displacement.

[Clinical risk factors of cesarean scar pregnancies]

Objective: To explore the risk factors related to cesarean scar pregnancies (CSP). Methods: Among the patients during July 2016 to June 2021 in Peking University Third Hospital, 596 cases of CSP patients were included as study group, and 1 192 cases of intrauterine pregnancy(IUP) women with history of cesarean section(s) were chosen as control group through stratified sampling according to the civil year of previous cesarean section matched with CSP group. The correlation between the general situation of patients, the history of gravidity and parity, the history of surgeries in uterine cavity and the previous cesarean section and the occurrence of CSP was explored through multivariate logistic regression analysis. Results: The current age of 596 CSP patients was (34.6±4.4) years, and that of 1 192 IUP patients was (35.6±3.6) years (P<0.001). Multivariate logistic regression analysis showed that the following factors may increase the risk of CSP: age<35 years old (OR=2.306, 95%CI: 1.774-2.998), history of medical abortion (OR=1.629, 95%CI 1.102-2.407), pregnancy interval<2 years from the last cesarean section (OR=2.147, 95%CI: 1.237-3.726), pregnancy interval ≥8 years from the last cesarean section (OR=1.474, 95%CI: 1.110-1.957), history of surgeries in uterine cavity before the last cesarean section (OR=2.558, 95%CI: 1.809-3.615), history of surgeries in uterine cavity after the last cesarean section (OR=8.020, 95%CI: 5.966-10.781), previous cesarean delivery ≥2 times (OR=14.051, 95%CI: 9.699-20.356) and history of previous cesarean sections before labor (OR=2.683, 95%CI: 1.930-3.731)(all P<0.05). Conclusions: The occurrence of CSP is related to the age of patients, the history of medical abortion, pregnancy interval, the history of surgeries in uterine cavity and the previous cesarean section, among which previous cesarean delivery ≥2 times and history of surgeries in uterine cavity after the last cesarean section are the strongly associated risk factors.

Propagation rules of shock waves in confined space under different initial pressure environments

In this paper, an initial pressure adjustable explosion vessel was developed, and the effect of negative pressure, positive pressure (0.2–1.8 atm) different initial ambient pressure on the explosive shock wave generated by the explosion of explosives was studied. The relationships between the specific impulse, shock wave velocity, the amount of explosive gas products and the ambient pressure were analyzed for different initial pressure environments. It was found that: the overpressure of the blast shock wave decreases with the initial ambient pressure of the explosion, and there exists a negative pressure environment with a dramatic pressure decrease near 0.6 atm, defined as the super-sensitive negative pressure P_cr. The propagation velocity of an explosive wave increases with a decrease in the ambient pressure, and the propagation velocity at a pressure of 1.8 atm is four times less than the velocity at a pressure of 0.2 atm. The production of explosive gas products did not change. The greater the initial pressure of the environment where the explosive is located, the smaller the ratio of the gas generated by the explosion to the initial force gas in the explosion vessel is, and the greater the impact on the propagation of shock waves is. The maximum attenuation of the first specific impulse i₁ is 72.97% and the maximum attenuation of the second specific impulse i₂ is 72.39%. The experiments provide reference data for high-altitude military confrontation, high-altitude weapons and ammunition development, and deep-earth protection engineering.

[Outcomes of patients experiencing cardiovascular adverse events within 1 year following craniotomy for intracranial aneurysm clipping: a retrospective cohort study]

OBJECTIVE

To investigate the impact of postoperative serious cardiovascular adverse events (CAE) on outcomes of patients undergoing craniotomy for intracranial aneurysm clipping.

METHODS

This retrospective cohort study was conducted among the patients undergoing craniotomy for intracranial aneurysm clipping during the period from December, 2016 to December, 2017, who were divided into CAE group and non-CAE group according to the occurrence of Clavien-Dindo grade ≥II CAEs after the surgery. The perioperative clinical characteristics of the patients, complications and neurological functions during hospitalization, and mortality and neurological functions at 1 year postoperatively were evaluated. The primary outcome was mortality within 1 year after the surgery. The secondary outcomes were Glasgow outcome scale (GOS) score at 1 year, lengths of postoperative hospital and intensive care unit (ICU) stay, and Glasgow coma scale (GCS) score at discharge.

RESULTS

A total of 361 patients were enrolled in the final analysis, including 20 (5.5%) patients in CAE group and 341 in the non-CAE group. No significant differences were found in the patients' demographic characteristics, clinical history, or other postoperative adverse events between the two groups. The 1-year mortality was significantly higher in CAE group than in the non-CAE group (20.0% vs 5.6%, P=0.01). Logistics regression analysis showed that when adjusted for age, gender, emergency hospitalization, subarachnoid hemorrhage, volume of bleeding, duration of operation, aneurysm location, and preoperative history of cardiovascular disease, postoperative CAEs of Clavien-Dindo grade≥II was independently correlated with 1-year mortality rate of the patients with an adjusted odds ratio of 3.670 (95% CI: 1.037-12.992, P=0.04). The patients with CEA also had a lower GOS score at 1 year after surgery than those without CEA (P=0.002). No significant differences were found in the occurrence of other adverse events, postoperative hospital stay, ICU stay, or GCS scores at discharge between the two groups (P > 0.05).

CONCLUSION

Postoperative CAEs may be a risk factor for increased 1-year mortality and disability in patients undergoing craniotomy for intracranial aneurysms.

[Analysis of clinical features and surgical outcomes of petrous bone cholesteatomas]

Objective: To analyze the clinical features and surgical outcomes of petrous bone cholesteatomas (PBCs). Methods: Data from 39 PBCs patients treated in the Department of Otorhinolaryngology, Xijing Hospital from September 2011 to December 2017 were reviewed retrospectively, including 23 males, 16 femals, aged 12-71 years old, with the median age of 37. Clinical classifications, surgical methods, facial and hearing function, and intraoperative and postoperative complications were made summary analysis. Results: In this study, five patients were congenital PBCs and 34 patients were acquired PBCs. The common clinical symptoms were hearing loss (100%, 39/39), ear discharge/pus (89.7%, 35/39) and facial paralysis (46.2%, 18/39). According to Sanna's classification, 14 cases were supralabyrinthine, including three cases underwent transcochlear (TC) approach, six cases underwent transotic (TO) approach and five underwent translabyrinthine (TL) approach. 10 cases were infralabyrinthine, including eight cases underwent subtotal petrosectomy, one case underwent TO approach and one underwent TL approach.10 cases were massive, including seven cases underwent TC approach, three cases underwent TO approach. Five cases were infralabyrinthine-apical, including two cases underwent TC approach, two cases underwent TO approach, and one case underwent endoscope assisted infratemporal fossa type B. The degree of facial nerve (FN) dysfunction from high to low was massive (6/10), supralabyrinthine (8/14), infralabyrinthine-apical (2/5) and infralabyrinthine (2/10). 19 cases involved in facial nerve operation, three cases underwent FN decompression, four cases underwent FN rerouting, four cases underwent nerve grafting, and one case underwent facial-hypoglossal anastomosis. Preoperative FN involvement in 18 cases, and the FN function was improved in 14 cases after surgery. The improved rate of postoperative FN function was 77.8%. The bone conducted hearing retained 50.0% (14/28) postoperatively. Five cases with cerebrospinal fluid leak were managed by inserting free muscle plugs and cavity obliteration. Two cases with the cholesteatomas matrix involved the sigmoid sinus and the jugular bulb, and occlusion of the sigmoid sinus was performed. Postoperatively, two patients presented with synkinesis. The patients were followed up for 40 to 115 months, and there was no recurrence. Conclusions: There are no specific clinical manifestations for PBCs, thus, it is difficult in early diagnosis and treatment. According to Sanna's classification, preoperative FN and hearing function, the best surgical approach should be selected with minimal recurrences and perioperative morbidity.

Storage, patterns, and environmental controls of soil organic carbon stocks in the permafrost regions of the Northern Hemisphere

Large stocks of soil organic carbon (SOC) accumulated in the Northern Hemisphere permafrost regions may be vulnerable to climatic warming, but global estimates of SOC distribution and magnitude in permafrost regions still have large uncertainties. Based on multiple high-resolution environmental variables and a compiled soil sample dataset (>3000 soil profiles), we used machine-learning methods to estimate the size and spatial distribution of SOC for the top 3 m soils in the Northern Hemisphere permafrost regions. We also identified key environmental predictors of SOC. The results showed that the SOC storage for the top 3 m soil was 1079 ± 174 Pg C across the Northern Hemisphere permafrost regions (20.8 × 10⁶ km²), including 1057 ± 167 Pg C in the northern permafrost regions and 22 ± 7 Pg C in the Third Pole permafrost regions. The mean annual air temperature and NDVI are the main controlling factors for the spatial distribution of SOC stocks in the northern and the Third Pole permafrost regions. Our estimations were more accurate than the existing global SOC stock maps. The results improve our understanding of the regional and global permafrost carbon cycle and their feedback to the climate system.