Endoscopic retrograde appendicitis therapy vs. Laparoscopic appendectomy for uncomplicated acute appendicitis

Background and study aims: To assess the efficacy and clinical outcomes of endoscopic retrograde appendicitis therapy (ERAT) versus laparoscopic appendectomy (LA) for patients with uncomplicated acute appendicitis (AA). Patients and methods: We adopted propensity score matching (1:1) to compare ERAT and LA patients with uncomplicated AA from April 2017 to March 2020. We reviewed a total of 2880 patients with suspected acute appendicitis, of whom 422 patients with uncomplicated AA met the matching criteria (ERAT, 79; LA, 343), yielding 78 pairs of patients. Results: The rate of curative treatment within one year after ERAT was 92.1%; 95% CI, [83.8% - 96.3%]. The percentage of Visual Analog Scale (VAS) ≤ 3 at six hours after treatment was 94.7%; 95% CI [87.2% - 97.9%] in the ERAT group, and significantly higher than that in the LA group 83.3%; 95% CI [73.5% - 90.0%]. Median operative/procedure time and median hospital length of stay in the ERAT group were significantly lower compared to the LA group. At one year, the median recurrence time was 50 days (IQRs, 25-127) in the ERAT group. The overall adverse event rate was 24.3%; 95% CI [14.8% - 33.9%] in the LA group and 18.4%; 95% CI [9.7% - 27.1%] in the ERAT group, with no significant difference between the two groups. Conclusions: ERAT is a technically feasible method to treat uncomplicated AA compared to LA.

Numerical Modelling of Lithospheric Block-and-Fault Dynamics: What Did We Learn About Large Earthquake Occurrences and Their Frequency?

Dynamics of lithospheric plates resulting in localisation of tectonic stresses and their release in large earthquakes provides important information for seismic hazard assessments. Numerical modelling of the dynamics and earthquake simulations have been changing our view about occurrences of large earthquakes in a system of major regional faults and about the recurrence time of the earthquakes. Here, we overview quantitative models of tectonic stress generation and stress transfer, models of dynamic systems reproducing basic features of seismicity, and fault dynamics models. Then, we review the thirty-year efforts in the modelling of lithospheric block-and-fault dynamics, which allowed us to better understand how the blocks react to the plate motion, how stresses are localised and released in earthquakes, how rheological properties of fault zones exert influence on the earthquake dynamics, where large seismic events occur, and what is the recurrence time of these events. A few key factors influencing the earthquake sequences, clustering, and magnitude are identified including lithospheric plate driving forces, the geometry of fault zones, and their physical properties. We illustrate the effects of the key factors by analysing the block-and-fault dynamics models applied to several earthquake-prone regions, such as Carpathians, Caucasus, Tibet-Himalaya, and the Sunda arc, as well as to the global tectonic plate dynamics.

Soil Moisture Profiles of Unsaturated Colluvial Slopes Susceptible to Rainfall-Induced Landslides

In this work, we describe soil moisture profiles related to typical colluvial slopes that were involved in rainfall-induced shallow failures occurring in alpine and pre-alpine areas of the Friuli Venezia Giulia Region (NE Italy). The trend of the volumetric water content (θw) showed a general increase from the ground surface to the bottom soil layer, with two or three marked moisture peaks. The saturation degree (S) varied from 65–70% (topsoil horizon) to nearly saturated basal colluvium (S = 95–100%). Soil moisture data demonstrates that, for a very humid climate, colluvial covers are often close to the saturation condition for most of the year. The calculated suction profiles indicated that maximum values ranging from 40 to 55 kPa often occur in the slope surficial soil (depth < 0.2–0.5 m). This negative pore-water pressure greatly decreases after a heavy rainfall event because of the infiltration process. Complete saturation of colluvial cover in the alpine and pre-alpine regions generally requires rainfall exceeding 150–200 mm for a 24-h storm duration. This results in a recurrence time of Tr ≅ 5–10 years for critical rainfall episodes involving colluvial slopes in the Friuli Venezia Giulia Region. The case histories analyzed demonstrate the importance of performing a detailed lithostratigraphic analysis of the colluvial deposit in order to properly define the suction measurement points, which there should be more of than the three-point determinations usually reported in the literature (for example, z = 0.5, 1.0 and 1.5 m).

Time-Resolved Magnetic Resonance Angiography for Follow-Up of Treated Dural and Epidural Spinal Arteriovenous Fistula

Background Spinal arteriovenous fistulas (AVFs) are uncommon vascular malformations of spinal dural and epidural vessels. Actually digital subtraction angiography (DSA) is the gold standard for diagnosis and follow-up. The aim of this study is to demonstrate the validity of the multiphasic magnetic resonance angiography (MRA) to identify recurrent/residual AVFs or their correct surgical and/or endovascular closure. Methods A retrospective cases series with perimedullary venous plexus congestion due to spinal dural or epidural AVF was performed at our center from April 2014 to September 2019. After 1 month from treatment, the patients were subjected to time-resolved MRA and DSA to demonstrate recurrence or correct closure of AVFs. Results We collected a series of 26 matched time-resolved MRA and DSA in 20 patients who underwent an endovascular and/or surgical procedure. In our series, we reported five cases of recurrence. Time-resolved MRA detected six cases of recurrence, with 100% sensitivity and 95% specificity (p < 0.001). We used DSA as the standard reference. Conclusion Time-resolved MRA is a valid tool in posttreatment follow-up to detect recurrent or residual AVFs. It has high sensitivity and specificity and may replace DSA.

An Introspective Overview of the Dynamics of Recurrent Events Data Analysis

A recurrent event remains the outcome variable of interest in many biometric studies. Recurrent events can be explained as events of defined interest that can occur to same person more than once during the study period. This study presents an overview of different pertinent recurrent models for analyzing recurrent events. Aims: To introduce, compare, evaluate and discuss pros and cons of four models in analyzing recurrent events, so as to validate previous findings in respect of the superiority or appropriateness of these models. Study Design: A comparative studies based on simulation of recurrent event models applied to a tertiary data on cancer studies. Methodology: Codes in R were implemented for simulating four recurrent event models, namely; The Andersen and Gill model; Prentice, Williams and Peterson models; Wei, Lin and Weissferd; and Cox frailty model. Finally, these models were applied to analyze the first forty subjects from a study of Bladder Cancer Tumors. The data set contained the first four repetitions of the tumor for each patient, and each recurrence time was recorded from the entry time of the patient into the study. An isolated risk interval is defined by each time to an event or censoring. Results: The choice and usage of any of the models lead to different conclusions, but the choice depends on: risk intervals; baseline hazard; risk set; and correlation adjustment or simplistically, type of data and research question. The PWP-GT model could be used if the research question is focused on whether treatment was effective for the event since the previous event happened. However, if the research question is designed to find out whether treatment was effective for the event since the start of treatment, then we could use the PWP- TT. The AG model will be adequate if a common baseline hazard could be assumed, but the model lacks the details and versatility of the event-specific models. The WLW model is very suitable for data with diverse events for the same person, which underscores a potentially different baseline hazard for each type. Conclusion: PWP-GT has proven to be the most useful model for analyzing recurrent event data.

Evaluation of patient social support, caregiver burden, and their relationship with the course of the disease in patients with bipolar disorder

Background: Bipolar disorder is a chronic disorder that causes significant effects on the patient and exerts a significant care burden on caregivers. This study aimed to investigate the social support of patients, caregivers’ burden and their impact on the clinical course of the disease. Methods: The study included 85 patients with bipolar disorder type I and II (in the recovery phase of the disease) and their caregivers in the age range of 18 to 60 years. It was conducted in Shafa psychiatry Hospital in Rasht (Guilan, Iran, 2020). To assess social support and burden, patients and caregivers completed the Multidimensional Perceived Social Support Scale (MSPSS) and Caregiver Burden Inventory (CBI), respectively. Clinical variables were also obtained from patients’ medical records; Then ANOVA, MANOVA, Independent T-test were used to compare the data and Regression Analysis and Spearman correlation coefficient were used to find the relationships between variables. Results: It was showed that increasing patient social support is associated with reducing caregiver burden. Among the clinical variables, less social support and more caregiver burden were associated with longer duration of illness ( p < .0029, p < .012), decrease in last recurrence time ( p < .0013, p < .0001), increased number of hospitalizations ( p < .0001, r = −.43 and p < .0001, r = +.49), decreased response to treatment ( p < .0001, p < .0001), and reduced follow-up ( p = .001, OR = 1.12 and p = .001, OR = 0.95). Conclusion: The relationship between low social support and high caregiver burden and their significant effect on the disease course indicates a vicious cycle that affects patients, caregivers, and the clinical course of the disease. Therefore, it seems that interventions to break this cycle can change the situation in favor of patients and caregivers and improve the clinical course of the disease.

Effects of the Nuclear Equation of State on Type I X-Ray Bursts: Interpretation of the X-Ray Bursts from GS 1826–24

Type I X-ray bursts are thermonuclear explosions on the neutron star (NS) surface caused by mass accretion from a companion star. Observations of X-ray bursts provide valuable information on X-ray binary systems, e.g., binary parameters, the chemical composition of accreted matter, and the nuclear equation of state (EOS). There have been several theoretical studies to constrain the physics of X-ray bursters. However, they have mainly focused on the burning layers above the solid crust of the NS, which brings up issues of the treatment of NS gravitational and internal energy. In this study, focusing on the microphysics inside NSs, we calculate a series of X-ray bursts using a general-relativistic stellar-evolution code with several NS EOSs. We compare the X-ray-burst models with the burst parameters of a clocked burster associated with GS 1826–24. We find a monotonic correlation between the NS radius and the light-curve profile. A larger radius shows a higher recurrence time and a large peak luminosity. In contrast, the dependence of light curves on the NS mass becomes more complicated, where neutrino cooling suppresses the efficiency of nuclear ignition. We also constrain the EOS and mass of GS 1826–24, i.e., stiffer EOSs, corresponding to larger NS radii, are not preferred due to a too-high peak luminosity. The EOS and the cooling and heating of NSs are important to discuss the theoretical and observational properties of X-ray bursts.

Salvage Radiotherapy Strategy and Its Prognostic Significance for Patients With Locally Recurrent Cervical Cancer After Radical Resection: a Retrospective 10-year Analysis

Background: Salvage radiotherapy modes for treating patients with local cervical cancer recurrence after radical surgery are controversial. Therefore, we aimed to evaluate the clinical efficacy and prognostic significance of two radiotherapy modes—involved-field radiotherapy combined with regional lymph nodes (regional radiotherapy) and involved-field radiotherapy alone (local radiotherapy)—in these patients.Methods: We retrospectively enrolled patients with local recurrence who underwent radical surgery without radiotherapy for early-stage cervical cancer from January 2010 to January 2020. Clinical outcomes were analyzed using the Kaplan–Meier method and a Cox proportional hazards model.Results: Forty-four patients underwent intensity-modulated radiotherapy (IMRT)-based salvage treatment. The 5-year overall survival and progression-free survival rates were 64% and 60.2%, respectively. Sixteen of 18 patients with stump recurrence and 15 of 26 patients with pelvic and abdominal cavity recurrence received regional radiotherapy, while others received local radiotherapy. Univariate analysis showed that patients with stump recurrence, who underwent regional radiotherapy, and with a lower systemic inflammation response index (SIRI) had better prognosis than their counterparts. Patients aged < 51 years, with stump recurrence, recurrence time ≤ 24 months, recurrence site=1, and a lower SIRI who received regional radiotherapy had a better prognosis than patients who received local radiotherapy. SIRI correlated with the recurrence site and radiotherapy mode.Conclusion: Locally recurrent cervical cancer treated with IMRT-based salvage therapy has a good prognosis. Recurrence site, SIRI, and the radiotherapy mode significantly influenced prognosis. Regional radiotherapy may be suitable for patients with stump recurrence, recurrence time ≤ 24 months, and one recurrence site.

Quest for the Upcoming Periastron Passage of an Episodic Dust Maker and Particle-accelerating Colliding-wind Binary: WR 125

We have carried out a long-term infrared and X-ray investigation of the colliding-wind binary WR 125 (WC7 + O9III). The source was monitored using AstroSat Soft X-ray Telescope and the Tata Institute of Fundamental Research Near Infrared Imaging Camera-II mounted at the back of 3.6 m Devasthal Optical Telescope. WR 125 appeared brighter in the near-infrared K-band during the years 2017–2021 which is attributed to another episode of dust formation similar to the one reported during the likely periastron passage at the beginning of the 1990s. This is further supported by enhanced emission observed in the W1 and W2 bands of Wide-field Infrared Survey Explorer from 2018–2019. By combining archival X-ray data sets with our new measurements, long-term variations have been noticed. The source reaches a lower emission state in 2020 June (close to the recent infrared maximum) which could be due to enhanced absorption of X-rays produced in the colliding-wind region by the WC stellar wind close to the periastron in an eccentric orbit. The time interval between the previous and latest X-ray low states may indicate an orbital period of 28–29 years, in fair agreement with the recurrence time of episodic dust production. We also discuss published radio measurements in the context of a common picture based on a long-period binary scenario. These results allow us to draw relevant guidelines for future multiwavelength observations of WR 125.

Development of a Global Spatio-Temporal Seismicity Model and Its Application to the Vrancea Seismic Zone, Romania

<p>This study investigates the temporal behaviour of major earthquakes in the Vrancea Seismic Zone (VSZ)in Romania. I used the Romplus catalogue, which is a compilation of several sources and spans the time from 984 AD to the year 2005 and in which the data are of different quality. This catalogue contains only Vrancean earthquakes and consists of more than 8000 events. Qualities 'A', 'B' and 'C' were used to model the data. 'D' and '=' were found as too unreliable for modeling. Using the b-value, I concluded that 3.5 is the correct cut-off magnitude for earthquakes after 1980 and at depths of 60 km and greater. Thereby I detected an increase in the b-value after 1986 of about 0.2 units. The reason for this increase could not be found. Plotting the Gutenberg-Richter relation for several time and depth intervals, it was found that at larger depths than 60 km, there are too many M7 earthquakes as compared to small shocks. The shape of the Gutenberg-Richter relation is similar as to the one expected by the characteristic earthquake model (Schwarz and Coppersmith, 1984; Wesnousky, 1994). A strike of 53 degree was found and the earthquake coordinates were rotated correspondingly. The resulting view on the slab showed the confined volume in which the earthquakes happen and well as the 'aseismic part' of the slab between 40 km and 60 km of depth. The seismicity seems to reach a depth of 180 km. Only the earthquakes in the slab, below a depth of 60 km, show clustering behaviour. Furthermore, the M7 earthquakes all happened in the slab. Thus, a depth limit of 60 km was introduced for modeling. In order to find aftershocks in the catalogue, the temporal behaviour of the Vrancea earthquakes was examined. The mean magnitude increases after each major earthquake, indicating an aftershock process. This was confirmed by the rate of occurrence, which showed an increase in rate after the 1990 earthquakes. The rate of occurrence is too low for the first 580 days after 1980, possibly due to insufficient earthquake detection in this period of time. All the damaging M7 earthquakes all happened in the slab. Thus, shallow earthquakes had to be considered separately. A depth limit of 60 km was introduced and earthquake in shallower and deeper depths were considered separately. For the shallow earthquakes there was a sharp increase in the apparent b-value below the cut-off magnitude of 3.5. After reaching a value of 2.4, the b-value starts to fall steeply. This was attributed to biases in the magnitude calculation. I used the rounded value of 3.5 as a cut-off magnitude for the shallow earthquakes. Having found the magnitude cut-off, depth and time limit, modeling could be started. The model gives two important parameters: the proportion of aftershock and the time to the next earthquake. Using the Maximum Likelihood Method, a best fit was found for a data set starting at 1980 and consisting of earthquakes with a cut-off magnitude of 3.5 and a depth equal and greater than 60 km. According to the model, this data set consists of 13 plus or minus 5% aftershocks and has an inter-event time for new earthquakes of 13 plus or minus 1 days. Using several cut-off magnitudes, it was found that the calculated inter-event time for these earthquakes is consistent with the Gutenberg-Richter law. In contrast, the predicted value for the interevent time of M7 earthquakes does not match the one found in the catalogue. While the Maximum Likelihood Method leads to 814 years as recurrence time, the data shows a recurrence time of only 23 years. The model fits the data set of the 1990 aftershocks very well, too, leading to a aftershock proportion of 58 plus or minus 15%. The data set for the 1986 did not lead to good results, probably due to missing aftershocks shortly after the main shock. Comparing model and data with a pure Poisson model I could see that earthquakes tend to cluster in the first days after the major event. Several days later, their behaviour changes and then is similar to the one proposed by the seismic gap model. Looking at the ratio between the probabilities of the model of Smith and Christophersen and of the Poisson model, a clustering behaviour in the first 24 hours after the main shock was found, followed by a decreased seismicity, which reverts to be Poissonian after 100 days. Thus, I concluded that aftershock behaviour is only relevant after the first 24 hours following a major earthquake. After 24 hours, seismic hazard decreases to be less than as expected by the Poisson model in the following 100 days, until seismicity returns to be Poissonian again. Additionally, I suggest that the 1990 earthquake and its aftershocks should be considered as a 'model earthquake' for future earthquakes as it seems to be representative for earthquake behaviour in the VSZ.</p>