Search Results (79)

Compared to antennas bearing a single port, MIMO antennas with several ports enable higher data throughput by exploiting spatial diversity. This capability is essential for next-generation implantable medical devices, where high channel capacity is a key requirement. A quad-element implantable MIMO antenna is designed and practically validated at 1420 MHz in this paper. It occupies a compact volume of $7\times 8\times 0.1 {\mathrm{mm}}^3$ ($5.6 {\mathrm{mm}}^3$). The compactness is realized by combining high-permittivity substrate (Rogers 3010 with relative permittivity of 10.2) with meandered radiator paths, which increase the effective current length while maintaining a small physical size. All antennas have very small mutual coupling with isolation of more than $31.78$ dB, which is mainly due to the spacing of 1 mm between the elements and the substrate, which is thin. The peak realized gain for each antenna element is $-27.3$ dBi. The simulation is performed within a capsule-like structure, which is embedded in the stomach tissue model. The experimental verification is carried out by embedding antenna within minced meat. The ECC, channel capacity, and link margin are also evaluated and found to be satisfactory. The proposed antenna ensures reliable communication performance, with the transmission range being as high as $2.5$ m, link margin being 15 dB, and the data rate being 120 Mb/s. The proposed antenna ensures a good level of ECC, which is less than $0.1$. The SAR is $52.3$ W/kg at 1420 MHz. This design is favorable for implants because of the small size, good impedance matching, high isolation, low correlation, good level of gain, and good link performance. Full article

Post-weaning diarrhea caused by Enterotoxigenic Escherichia coli (ETEC) is a major disease in piglets and leads to substantial economic losses in the swine industry. Compared to conventional lysozyme, yak stomach lysozyme (YSL) demonstrates distinctive resistance to pepsin, trypsin, high temperature, and acidic conditions. This study investigated the effects of dietary YSL supplementation on intestinal health in weaned piglets challenged with ETEC, utilizing metabolomics and proteomics. A total of 18 weaned piglets were randomly divided into three groups: control (C), diarrhea (D), and YSL treatment (YLT). Groups C and D were fed a basal diet, while the YLT group received the basal diet supplemented with YSL at a dosage of 100,000 U/kg following ETEC challenge. Following an acclimation period, piglets in groups D and YLT were orally challenged with ETEC, while group C received the same volume of sterile LB broth. The feeding trial lasted for 21 days before sample collection. The results demonstrated that dietary supplementation with YSL significantly reduced the diarrhea rate (p < 0.05). Compared with the D group, the YLT group exhibited significantly increased serum albumin levels (p < 0.05), along with a tendency toward greater villus height (p = 0.085) and higher serum glucose levels (p = 0.052), indicating an improvement in nutritional and metabolic status Metabolomic analysis identified 260 differentially abundant metabolites between the YLT and D groups (81 upregulated, 179 downregulated), which were predominantly enriched in pathways related to amino acid biosynthesis and metabolism, purine metabolism, and nucleic acid metabolism. Proteomic profiling revealed 571 differentially expressed proteins (237 upregulated, 334 downregulated). Upregulated proteins were mainly involved in arginine biosynthesis and base excision repair, while downregulated proteins were associated with the PPAR signaling pathway and Salmonella infection. In summary, dietary YSL supplementation alters the metabolic and proteomic profiles in the intestines of diarrheic piglets, potentially improving gut barrier function and nutrient utilization. This study offers novel insights into the potential of YSL as a promising feed additive for prevention of post-weaning diarrhea in pigs. Full article

Background: One of the challenges in treating pancreatic ductal adenocarcinoma (PDAC) with stereotactic radiotherapy (SRT) is to manage lesions abutted to the duodenum, bowel and stomach. Simultaneous integrated protection (SIP) is one of the proposed approaches to increase plan reproducibility and quality. However, no clinical data are available regarding the dosimetric objectives impacting local control probability. Methods: This is a prospective, single-arm study. Key inclusion criteria were as follows: PDAC histology; tumor abutment with duodenum, stomach, or small bowel; and SRT schedule consisting of 45 Gy in six fractions. Delineation of the PTV overlapped with critical OARs (PTV_SIP) and PTV outside critical OARs (PTV_Dominant) was mandatory. Dose constraints were as follows: (near) maximum dose, D2cc, and D20cc to critical OARs 38 Gy, 32 Gy, and 24 Gy, respectively. This study was designed to prospectively investigate the main clinical and dosimetric parameters impacting freedom from local recurrence (FFLR). Results: From June 2019 to January 2024, 104 patients were enrolled. One-year FFLR was 91.7%. Fifteen events of local failure occurred (17.6%). Mapping of local relapses showed a relapse inside the PTV_SIP area in nine patients and outside the PTV_SIP in six cases (NS). Whole PTV > 69 cc, PTV_SIP > 4 cc, PTV-SIP/whole PTV ratio > 7%, (near) Dmin to PTV_SIP < 25 Gy, mean dose to PTV_SIP < 28 Gy, and (near) Dmin to PTV_Dominant < 29 Gy were associated with worse FFLR. Multivariable analysis showed PTV_SIP absolute volume of more than 4 cc, mean dose to PTV_SIP < 28 Gy and whole PTV > 69 cc were independently related to worse FFLR. One case of acute G4 toxicity and two cases of acute G3 toxicity occurred, with two late toxicity deaths not certainly due to treatment. Conclusions: In this prospective study, SIP planning strategy with six fractions is safe and effective in pancreatic targets with critical contact with critical OARs. Given its potential advantages, SIP planning is a potential innovative strategy that should be compared to standard SRT planning in an ad hoc trial design. Full article

Background and Objectives: Endoscopic sleeve gastroplasty (ESG) is a minimally invasive endoscopic procedure that has demonstrated both safety and effectiveness in the treatment of obesity. By reducing the stomach’s volume without the need for surgical incisions, ESG promotes weight loss and can improve obesity-related comorbidities. However, patient responses to ESG can vary significantly. Materials and Methods: A comprehensive search was performed on PubMed, Embase, and Cochrane for studies with endoscopic sleeve gastroplasty; the main outcomes of interest are BMI, weight loss, and postinterventional complications. The search strategy employed a combination of keywords and Medical Subject Heading (MeSH) terms, including “endoscopic sleeve gastroplasty,” “endoscopy,” and “overweight”. To ensure the thoroughness of the review, additional manual searches of key journals and the reference lists of identified studies were performed. Grey literature, such as dissertations and conference abstracts, meta-analysis, and systematic reviews, was excluded to maintain a focus on peer-reviewed evidence. Duplicate records were identified and removed using Rayyan software to streamline the screening process. The I2 test was employed for heterogeneity assessment, while the risk of bias was evaluated utilizing ROBINS-I. Results: Our literature search resulted in the inclusion of 38 studies. Endoscopic sleeve gastroplasty for weight loss is important since it is more effective than pharmacological treatments and lifestyle changes and presents lower adverse event rates compared to bariatric surgery. Long-term weight loss outcomes varied, with total body weight loss ranging from 16% to 20.9% over a period from 2 to 5 years, while excess weight loss ranged from 13% to 79%. Revisional procedures showed higher failure rates, with up to 34.3% of patients experiencing insufficient weight loss. Most interventions led to clinically significant and sustained weight loss, though variability in outcomes highlights the need for further research to optimize long-term weight management strategies. Conclusions: Endoscopic sleeve gastroplasty (ESG) emerges as a promising minimally invasive option for weight loss, offering significant improvements in both weight reduction and obesity-related comorbidities, such as diabetes, hypertension, and dyslipidemia. Full article

A zoo-housed alpaca was found recumbent with profuse frothy salivation and an inability to stand. Supportive treatment, including intravenous fluid therapy via the jugular vein and oral administration of activated charcoal, was initiated. Despite these interventions, the animal’s condition progressively worsened, with clinical signs including vomiting and neurological manifestations such as paddling movements and opisthotonus. The alpaca died approximately 4 h after discovery by first observation of clinical signs. Necropsy revealed a large volume of white, foamy fluid present in the tracheal and bronchial lumens. The lungs were dark red and markedly congested and edematous throughout all lobes. Multiple ecchymotic hemorrhages were observed on the mucosal surface of the pyloric region of the third compartment of the stomach and on the serosal surface of the duodenum. Histopathological examination revealed severe pulmonary congestion and edema, along with marked congestion of the liver, spleen, and kidneys. The gastric contents were green and contained plant material, including ten leaves morphologically identified as Japanese pieris (Pieris japonica). Postmortem inspection of the enclosure revealed the presence of Japanese pieris shrubs with evidence of browsing. Based on these findings, acute poisoning from ingestion of Japanese pieris was diagnosed. Full article

Bariatric surgery involves major changes in the anatomy and physiology of the gastrointestinal tract, which may alter oral drug bioavailability and efficacy. Phosphodiesterase-5 inhibitor (PDE5i) drugs are the first-line treatment of erectile dysfunction, a condition associated with a higher BMI. In this paper, we examine the PDE5i vardenafil for possible post-bariatric changes in solubility/dissolution and absorption. Vardenafil solubility was determined in vitro, as well as ex vivo using aspirated gastric contents from patients prior to vs. following bariatric procedures. Dissolution was tested in vitro under unoperated stomach vs. post-gastric sleeve/bypass conditions. Lastly, the gathered solubility/dissolution data were used to produce an in silico physiologically based pharmacokinetic (PBPK) model (GastroPlus^®), where gastric volume, pH, and transit time, as well as proximal GI bypass (when relevant) were all adjusted for, evaluating vardenafil dissolution, gastrointestinal compartmental absorption, and pharmacokinetics before vs. after different bariatric procedures. pH-dependent solubility was demonstrated for vardenafil with low (pH 7) vs. high solubility (pH 1–5), which was confirmed ex vivo. The impaired dissolution of all vardenafil doses under post-gastric bypass conditions was demonstrated, contrary to complete (100%) dissolution under pre-surgery and post-sleeve gastrectomy conditions. Compared to unoperated individuals, PBPK simulations revealed altered pharmacokinetics post-gastric bypass (but not after sleeve gastrectomy), with 30% lower peak plasma concentration (C_max) and 40% longer time to C_max (T_max). Complete absorption after gastric bypass is predicted for vardenafil, which is attributable to significant absorption from the large intestine. The biopharmaceutics and PBPK analysis indicate that vardenafil may be similarly effective after sleeve gastrectomy as before the procedure. However, results after gastric bypass question the effectiveness of this PDE5i. Specifically, vardenafil’s onset of action might be delayed and unpredictable, negatively affecting the practicality of the intended use. Full article

Background/Objectives: Duodenum-preserving pancreatic head resection (DPPHR) preserves digestive and absorptive functions better than pancreaticoduodenectomy (PD). Zinc is primarily absorbed in the duodenum and proximal jejunum and plays a critical role in nutritional maintenance and pancreatic regeneration. However, no studies have compared the postoperative pancreatic volume and serum zinc levels between DPPHR and PD. Methods: We retrospectively analyzed 41 patients who underwent DPPHR (n = 23) or subtotal stomach-preserving PD (n = 18) for low-grade pancreatic malignancies at our institution. The remnant pancreatic volumes on postoperative day 7 and 1 year were measured via computed tomography. Nutritional parameters, including serum albumin, prognostic nutritional index (PNI), and serum zinc levels, were compared between the groups. Serum zinc levels were evaluated in patients with DPPHR (n = 11) or PD (n = 7). Results: The DPPHR group demonstrated significantly better preservation of remnant pancreatic volume on postoperative day 7 and 1 year compared to the PD group (p = 0.045 and p = 0.041, respectively). Volume maintenance ratios were also significantly higher in the DPPHR group. Serum albumin levels at 1 year postoperatively were significantly better in the DPPHR group, although no significant difference was found in the PNI. Among patients evaluated for serum zinc, the DPPHR group showed significantly higher zinc levels compared to the PD group (80.3 vs. 65.8 μg/dL, p = 0.017). Conclusions: DPPHR preserves remnant pancreatic volume and maintains serum zinc levels better than PD, potentially contributing to improved postoperative nutritional status and quality of life. Further prospective studies with larger cohorts are warranted to validate these findings. Full article

(1) Background: We combined physiological and morphological data of the European rabbit (Oryctolagus cuniculus) to provide insights into the question of how urbanization affects the health of urban wildlife populations. (2) Methods: We dissected 39 urban and 34 rural wild rabbits in order to compare organ weights, as well as stomach contents. Furthermore, we collected blood and fecal samples. (3) Results: Rural rabbits had a significantly longer body and a higher body weight as well as more fat tissue around their kidneys compared to urban rabbits. In contrast, the stomach, the intestines, the liver, the lung, and the brain of urban rabbits were significantly heavier. The amount of hematocrit, hemoglobin, and the mean corpuscular volume was significantly higher in urban rabbits. The caloric energy content of the stomach was comparable between rural and urban rabbits and was merely influenced by the season being higher in autumn. Rural rabbits had an overall higher mean parasite index compared to urban rabbits. (4) Conclusions: The results of our study allow for a deeper understanding of how density-dependent (e.g., transmission of diseases) and density-independent factors (e.g., food quality) influence the health status and life history traits of urban wildlife populations compared to their rural counterparts. Full article

Background/Objectives: Stereotactic body radiotherapy is frequently used in patients with adrenal metastases. Motion of adherent radiosensitive organs at risk (OARs) and tumors influence OAR toxicity and tumor control. Online-adaptive Magnetic Resonance-guided radiotherapy (MRgRT) can address and mitigate interfractional changes. However, the impact of intrafractional variations in adrenal MRgRT is unknown. Methods: A total of 23 patients with 24 adrenal metastases were treated with MRgRT. After daily plan adaptation and before beam application, an additional (preRT) 3d MRI was acquired. PreRT target volumes and OARs were retrospectively recontoured in 200 fractions. The delivered, online-adapted treatment plans, as well as non-adapted baseline plans, were calculated on these re-contoured structures to quantify the dosimetric impact of intrafractional variations on target volume coverage and OAR doses with and without online adaptation. Normal tissue complication probabilities (NTCPs) were calculated. Results: The median time between the two MRIs was 56.4 min. GTV and PTV coverage (dose to 95% of the PTV, D95%, and volume covered by 100% of the prescription dose, V100%) were significantly inferior in the preRT plans. GTV D_mean was significantly impaired in left-sided metastases, but not in right-sided metastases. Compared to non-adapted preRT plans, adapted preRT plans were still significantly superior for all GTV and PTV metrics. Intrafractional violations of OAR constraints were frequent. D0.5cc and the volume exposed to the near-maximum dose constraint were significantly higher in the preRT plans. The volume exposed to the D0.5cc constraints in single fractions escalated up to 1.5 cc for the esophagus, 3.2 cc for the stomach, 5.3 cc for the duodenum and 7.3 cc for the bowel. This led to significantly elevated NTCPs for the stomach, bowel and duodenum. Neither PTV D95%, nor gastrointestinal OAR maximum doses were significantly impaired by longer fraction duration. Conclusions: Intrafractional motion in adrenal MRgRT caused significant impairment of target volume coverage (D95% and V100%), potentially undermining local control. Frequent violation of gastrointestinal OAR constraints led to elevated NTCP. Compared to non-adaptive treatment, online adaptation still highly improved GTV and PTV coverage. Full article

Background/Objectives: Insufflation of the gastrointestinal tract, as a side effect of improper ventilation, is a known complication in resuscitation patients. As animal studies have shown, this can be associated with an increase in intra-abdominal pressure with adverse effects on hemodynamics and respiratory mechanics. In this study, we investigated the prevalence and severity of insufflation and discussed the potential impact on the outcome of resuscitation. Methods: This study was based on computed tomography (CT) images from two university hospitals in Munich, Germany, which were taken as part of the trauma room care of out-of-hospital cardiac arrest (OHCA) patients. According to local resuscitation protocol, CT performed during ongoing cardiopulmonary resuscitation or after the return of spontaneous circulation (ROSC) was archived to determine the potentially reversible cause of cardiac arrest. CT images from 2014 to 2018 were analyzed in this study. Using an advanced visualization and analysis platform for medical image data, the gas volume within the gastrointestinal tract was determined and compared between resuscitations with lethal and secondary survival outcomes. Results: A total of 92.44% of included OHCA patients (n = 172) showed signs of increased gastrointestinal gas volume in comparison to the physiologically prevalent gas volume. In OHCA patients with a lethal outcome, significantly more gas was detected in the gastrointestinal tract with a median of 757.40 mL compared to 380.65 mL in resuscitations with secondary survival (p ≤ 0.05; W = 4278). Furthermore, Cohen’s r was used to calculate the effect size, indicating a weak association with the outcome of resuscitation (r = 0.24). In addition, a logistic regression analysis was performed to examine the influence of age, gender (female), and the gas volume of the intestines and stomach on the dependent variable “death”. The analysis shows that the model, as a whole, is significant (Chi² = 17.67; p 0.02; n = 172) and supports the hypothesis that intestinal insufflation correlates with a lethal outcome from resuscitation (b = 0.001; OR 1.001 (95% CI [1.000–1.002]; p = 0.021). Conclusions: Insufflation in resuscitation patients is a common phenomenon with potential consequences for the outcome. Even if the effect we have shown appears small, the outcome of resuscitation patients can possibly be improved by preventing or correcting insufflation. To understand its potential impact on resuscitation outcomes fully, further work must be performed to investigate causality. Full article

Aripiprazole (ARZ) is an atypical antipsychotic drug used to treat a variety of mood and psychotic disorders, such as schizophrenia, bipolar disorder, major depressive disorder, autism, and Tourette’s syndrome. Although ARZ offers significant therapeutic benefits, its poor solubility in water requires the development of delivery systems aimed at improving the solubility and bioavailability of the drug. In this work, cryogels based on two natural products—agar and β-cyclodextrin (CD)—were developed and evaluated as a drug delivery system for ARZ. The cryogels were prepared by cryogenic treatment of aqueous solutions of agar and the β-CD/ARZ complex, followed by thawing. The main characteristics of the material, including gel fraction yield, swelling degree, pore volume, elastic properties, and morphology were studied in detail. The release of ARZ from composite cryogels was assessed in two media resembling the pH in stomach and intestine. The system exhibited a pH-dependent release of ARZ, with a slower rate in acidic media (pH 1.2) than in the neutral phosphate buffer (pH 6.8). Under in vitro conditions, the amount of released ARZ over 48 h reached 33%. Full article

Background: The development of nanostructured materials for cancer therapy has garnered significant interest due to their unique physicochemical properties, including enhanced surface area and tunable electronic structures, which can facilitate targeted drug delivery and oxidative stress modulation. This study investigates the anticancer potential of monoclinic silver dimolybdate nanorods (m-Ag₂Mo₂O₇) against aggressive breast (MDA-MB-231) and prostate (PC-3) cancer cells and explores their in vivo pharmacokinetic behavior. Methods: m-Ag₂Mo₂O₇ nanorods were synthesized via a hydrothermal method and characterized using XRD, SEM, Raman, and FTIR spectroscopy. In vitro cytotoxicity was evaluated using MTT assays on MDA-MB-231 and PC-3 cell lines across concentrations ranging from 1.56 to 100 µg/mL. In vivo biodistribution and radiopharmacokinetics were assessed using technetium-99m-labeled nanorods in male Swiss rats, with gamma counting employed for tissue uptake analysis and pharmacokinetic parameter determination. Results: m-Ag₂Mo₂O₇ nanorods exhibited a modest cytotoxic effect on MDA-MB-231 cells, with 50 µg/mL reducing cell viability by 23.5% (p < 0.05), while no significant cytotoxicity was observed in PC-3 cells. In vivo studies revealed predominant accumulation in the stomach, liver, spleen, and bladder, indicating reticuloendothelial system uptake and renal clearance. Pharmacokinetic analysis showed a rapid systemic clearance (half-life ~6.76 h) and a low volume of distribution (0.0786 L), suggesting primary retention in circulation with minimal off-target diffusion. Conclusions: While m-Ag₂Mo₂O₇ nanorods display limited standalone cytotoxicity, their ability to induce oxidative stress and favorable pharmacokinetic profile support their potential as adjuvant agents in cancer therapy, particularly for chemoresistant breast cancers. Further studies are warranted to elucidate their molecular mechanisms, optimize combinatorial treatment strategies, and assess long-term safety in preclinical models. Full article

Background/Objectives: Despite standard preoperative fasting guidelines, residual gastric content can persist in some patients, increasing the risk of aspiration pneumonitis. Multiple patient-specific factors may predict gastric content retention, but their predictive accuracy is limited. We hypothesized that ultrasound would more reliably identify residual gastric content compared to a comprehensive questionnaire and aimed to determine the most practical approach for risk assessment in elective surgical patients. Methods: We conducted a prospective, observational study in adult patients scheduled for elective surgery at a single center. All participants adhered to an 8 h fasting period. The primary outcome was the incidence of a “full stomach” on ultrasound. Secondary outcomes included the Perlas risk classification, comparisons of established volume estimation formulas, correlations with self-reported fasting duration, agreement between questionnaire-based predictions and ultrasound findings, and the time efficiency of each method. Multivariable logistic regression and Cohen’s kappa were used for analyses. Results: Data from 404 patients were analyzed. Despite prolonged fasting, 16.3% had a full stomach by ultrasound, suggesting incomplete gastric emptying. Early satiety and cholelithiasis significantly predicted a full stomach; prolonged fasting duration and female sex were protective. Questionnaire-based predictions demonstrated fair agreement with ultrasound (kappa = 0.327). The Michiko formula often yielded negative volumes, highlighting limitations in volume estimations. Ultrasound examination (3 min median) was faster than questionnaire completion (5 min). Conclusions: Ultrasound accurately detects residual gastric content, outperforming questionnaire-based assessments. Integrating it into routine preoperative evaluation may improve patient safety, although research is needed to refine volume estimation formulas and expand feasibility for patients with positioning limitations. Full article

Background: Studies have demonstrated that resveratrol exerts several pharmacological effects. However, the pharmacokinetic parameters are not completely established. Objectives: This study describes the plasma pharmacokinetics and tissue distribution of resveratrol after administration by different routes and doses in rats. Methods: A reliable, simple, and sensitive HPLC method using UV detection for the quantification of resveratrol in rat plasma and tissues was developed and validated. In addition, a pharmacokinetic analysis using non-compartmental and population modeling was performed. Results: The pharmacokinetic parameters of resveratrol after the administration of 5 mg/kg via i.v. bolus calculated by non-compartmental analysis were a constant of elimination (ke) of 0.09 h⁻¹ ± 0.04, a half-life (t1/2) of 9.5 h ± 3.7, an apparent volume of distribution (Vd) of 5.8 L/kg ± 4.7, a clearance (Cl) of 0.39 L/h/Kg ± 0.26, and an area under the curve (AUC) of 6076 ng/h/mL ± 2959. The results obtained after the administration of 100 mg/kg p.o. were an elimination constant (ke) of 0.12 ± 0.07 h⁻¹, a half-life (t1/2) of 7.9 ± 4.2 h, the apparent volume distribution (Vd) of 13.3 ± 3.3 L/kg, a clearance (Cl) of 1.76 ± 0.49 L/h/Kg ± 0.26, and an area under the curve (AUC) of 6519 ± 1592 ng/h/mL. For the tissue distribution analysis, 10 mg/kg of resveratrol was intravenously administered to rats and the molecule was quantified in the liver, lung, kidney, heart, stomach, spleen, adipose tissue, and brain of the animals. Conclusions: The population pharmacokinetic modeling showed that resveratrol has a two-compartment model in both routes of administration and has a higher volume of distribution when it is given orally. In addition, resveratrol showed a high brain concentration after iv administration, which indicates that this molecule is capable of crossing the blood–brain barrier of animals, a crucial capacity for its neuroprotective activity. Full article

Rhamdiopsis krugi is a highly specialized troglobitic (exclusively subterranean) catfish endemic to the phreatic water bodies of twelve caves located within two separated metasedimentary basins in the region of Chapada Diamantina, Bahia state, Brazil. This species is included in the List of Endangered Fauna of Brazil, under the Vulnerable category—VU. In general, troglobites have different strategies for searching for food and reproductive partners, as well as unique behaviors. Knowledge of the reproductive periods, as well as its feeding habits, provides fundamental data for effective protection and species conservation. Biological aspects related to feeding habits and reproduction of R. krugi were addressed across six annual cycles, considering both dry and rainy seasons. For this, stomach content analysis, using the frequency of occurrence and volumetric index methods, as well as observation of the sex ratio and stage of maturation of the gonads were carried out for 148 individuals of R. krugi sampled in eight caves in Chapada Diamantina. Stomach volumes correlated with reproduction aspects across the dry and rainy seasons. These populations showed opportunistic carnivorous feeding habits, consuming both autochthonous and allochthonous items, with a preference for foraging in submerged guano deposits, which demonstrates the catfish’s strong dependence on bats. Regarding sex ratios, there was no marked seasonality; however, in rainy seasons, there was a higher proportion of maturing females, showing a reproductive tendency. During these periods, there was also a significantly higher number of stomachs with contents, showing seasonality in the diet. Specialized diet and dependence on rainy periods, especially in diet, corroborate the fragility of R. krugi, especially considering the changes in rainfall regimes in Brazil, with dry seasons exceeding eight months per year in the last ten years. Full article