Objective: To understand the awareness of chikungunya fever knowledge and its related factors among medical college students in Baise City, so as to provide a scientific basis to offer relevant courses and special education. Methods: From July to August 2025, 7 286 enrolled medical students were selected by a sampling method from a medical college in Baise City to participate in the questionnaire survey. The questionnaire covered epidemiological characteristics, clinical symptoms, and prevention/control knowledge of chikungunya fever. Statistical analyses including the Chi quare test and multivariate Logistic regression models were performed. Results: The overall awareness rate of chikungunya fever knowledge among the medical students was 18.89%. Among the knowledge items, the awareness rate of "the high incidence season" was the highest (84.05%), while that of "the infectious period" was the lowest (17.80%). Multivariate Logistic regression analysis showed that medical students with female (a OR= 1.37 , 95%CI =1.20- 1.57 ), the age for over 25 years old (a OR=1.76, 95%CI =1.05-2.93), whose father had a middle school educational level (a OR=1.18, 95%CI =1.05-1.31), and majored in preventive medicine (a OR=1.54, 95%CI =1.10-1.67) had relatively higher awareness rates of chikungunya fever knowledge (all P <0.05). In contrast, students of Zhuang ethnicity (a OR= 0.87 , 95%CI =0.76-0.98) and majoring in nursing (a OR=0.74, 95%CI =0.61-0.91) or pharmacy (a OR=0.70, 95%CI =0.52-0.95) had relatively lower awareness rates (all P <0.05). Conclusions The awareness rate of chikungunya fever related knowledge among medical college students in Baise City is relatively low. Schools should take targeted publicity measures to improve medical students awareness.

Olfactory receptors (ORs) form the largest superfamily of G protein-coupled receptors (GPCRs). Traditionally recognized for their role in the nasal olfactory epithelium, where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidneys. The intestine, as the primary site for nutrient digestion and absorption, harbors a highly complex chemical environment. To adapt to this environment, the gut employs a sophisticated network of “chemosensors” to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as crucial functional components, serving as a molecular bridge that connects environmental chemical signals—such as food-derived odorants—to specific physiological responses. This discovery has significantly deepened our understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Studies indicate that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a wide variety of ligands, including exogenous dietary components, gut microbiota metabolites such as short-chain fatty acids, and endogenous small molecules like azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to elucidate the molecular mechanisms by which these receptors regulate the secretion of gut hormones. Activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility. Furthermore, the review addresses the critical roles of ORs in immune regulation and pathology. Evidence suggests that specific ORs contribute to the maintenance of intestinal immune homeostasis and may offer protection against inflammation. Beyond their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation by remodeling the gut microbiome and metabolome. These findings collectively suggest that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and maintaining gut homeostasis. Additionally, the review explores the emerging role of ORs in cancer. Although OR expression is often downregulated in tumor tissues compared to normal mucosa, activation of specific ORs by certain ligands can inhibit tumor cell proliferation and migration and induce apoptosis via pathways such as MEK/ERK and p38 MAPK. Conversely, other receptors, such as OR7C1, may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut’s sensory network. The review also discusses the translational potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may thus emerge as promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases, and malignancies.

Objective This study aimed to investigate the seasonal variation of mosquitoes in Yantai, Shandong Province, and provide a scientific basis for mosquito and mosquito-borne disease control. Methods From March to November for each of the years between 2020 and 2023, adult mosquitoes were collected from different habitats, including parks, hospitals, urban residential areas, rural households and livestock sheds, in 13 counties of Yantai City using a mosquito trap lamp method, among which, female mosquitoes were separated and identified, and the numbers were counted. We used the circular distribution method to analyze the temporal distribution characteristics of mosquito density. Results The γ values obtained for mosquitoes in Yantai from 2020 to 2023, the distribution of mosquitoes in different habitats, and dominant mosquito species in different months showed strong seasonality, with values ranging from 0.7461 to 0.8531(P ＜ 0.05). The peak period of seasonal variation in mosquitoes occurred from June 28thto September 13th, with August 5thbeing identified as the peak day. The peak periods of seasonal variation in mosquitoes in residential areas, parks, hospitals, peasant households, and animals sheds were observed from June 24thto September 14th, June 25thto September 10th, June 22ndto September 12th, July 1stto September 9th, and July 2ndto September 17th, respectively, with corresponding peak days on August 4th,3rd, 2nd, 5th, and 9th, respectively. The peak periods of Culex pipiens pallens, Aedes albopictus, and Anopheles sinensis were from June 26thto September 11th, June 28thto September 17th, and July 12thto September 17th, respectively, with corresponding peak days on August 3rd,7th, and 14th, respectively. Conclusions Our findings in this study revealed that the peak of mosquito activity in Yantai was concentrated in early August, with a peak period extending from June 28thto September 13th, and there were differences between different habitats(with peak periods for rural households and livestock sheds occurring later than those in residential areas, parks, and hospitals). Moreover, with respect to the mosquito species, populations of Cx. pipiens pallens and Ae. albopictus peaked earlier than those of An. sinensis. Based on these findings, we recommend that city-wide mosquito control work should commence in late June, and include appropriate early prevention and control measures for key habitats, such as livestock sheds, and dominant mosquito species, such as Cx. pipiens pallens, to minimize the density of mosquito vectors and the risk of disease transmission.

ObjectiveTo investigate whether Bushen Huoxue prescription improves embryo implantation through regulating exosomal miRNA to enhance maternal-fetal interface communication based on Bushen Huoxue therapy. MethodsIn the animal experiment， all the rats （except for the blank group） were administered hydroxyurea （450 mg·kg^-1） via gavage for 10 d， as well as epinephrine （0.3 mg·kg^-1） and mifepristone （5.5 mg·kg^-1） via subcutaneous injection for 7 d to establish an implantation disorder model of kidney deficiency and blood stasis type. The Bushen Huoxue prescription （BSHX） groups were administered the prescription at different doses （7.30 g·kg^-1 for the high-dose group， 3.65 g·kg^-1 for the medium-dose group， and 1.83 g·kg^-1 for the low-dose group） via gavage. The dydrogesterone group was administered the corresponding medicine （2.63 mg·kg^-1） via gavage. After intervention for 10 days， uterine histopathological changes were observed via hematoxylin-eosin （HE） staining. Mucin （MUC1）， forkhead box protein O1 （FoxO1）， and homeobox A10 （HoxA10） expression levels were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. Cell experiment selected primary endometrial epithelial cells （EEC） and trophoblast cells （TC） as research subjects. Exosome-free medicated serum was prepared by ultracentrifugation and cultured in complete medium. Exosomes were isolated from cell supernatants by ultracentrifugation for cross-co-culture. After 48 h， migration and invasion abilities were assessed by scratch and Transwell assays. Sequencing was then performed on EEC-origin exosomal miRNA. ResultsThe model rats exhibited thin endometrium， along with reduced blood vessels， glandules， and pinopode numbers. BSHX improved endometrial morphology and increased pinopode numbers. MUC1， FoxO1， and HoxA10 expressions were downregulated in the model rats， while these parameters were upregulated after BSHX medium- and high-dose intervention. In the cell experiment， after exosome-free medicated serum intervention for 24 h， migration and invasion abilities were enhanced in the BSHX groups （P<0.01）. In EEC-origin exosomal miRNA sequencing， gene ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） analyses revealed enrichment in biological processes （gastrulation， neuronal differentiation， alongside cell development and regeneration）， involving the mitogen-activated protein kinase （MAPK）， FoxO1， Wnt， mammalian target of rapamycin （mTOR）， and tumor necrosis factor （TNF） signaling pathways. ConclusionBSHX promotes embryo implantation by improving endometrial receptivity via regulating exosomal miRNA. These findings provide potential targets for exosomal miRNA-based assisted reproductive strategies and a novel theoretical basis for infertility treatment by traditional Chinese medicine.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

OBJECTIVE To investigate the improvement effects of the Shenling kongliu formula （SLKLF） on mice with colorectal adenoma （CRA）， as well as its impact on the Toll-like receptor 4 （TLR4）/myeloid differentiation primary response protein 88 （MyD88）/nuclear factor-κB （NF-κB） pathway and on the macrophage polarization.METHODS Thirty male Apc Min/+ mice were randomly divided into a model group， an aspirin group [positive control， 20.59 mg/（kg·d）]， and low-， medium- and high-dose SLKLF groups [2.06， 4.11 and 8.22 g/（kg·d）]， with six mice in each group. Additionally， 6 wild-type male C57BL/6J mice were used as the wild-type control group. Mice in each group were gavaged twice daily with the corresponding drug solution or normal saline for 12 consecutive weeks. After the final administration， the levels of interleukin-10 （IL-10） and tumor necrosis factor-α （TNF-α） in the serum of mice in each group were measured， the total number of adenomas and the average longest diameter in the entire colon and rectum were counted， histopathological changes in colorectal tissues were observed， and the protein expressions of cluster of differentiation 86 （CD86）， CD206， inducible nitric oxide synthase （iNOS）， arginase-1 （ARG-1）， TLR4， MyD88， and NF-κB p65 in the colorectal tissue were detected.RESULTS Compared with the model group， mice in all SLKLF dose groups showed varying degrees of improvement in pathological changes such as colorectal adenomatous lesions and inflammatory cell infiltration. Their serum levels of IL-10 and TNF-α， total number of adenomas and their average longest diameter （except in the low-dose group）， CD86-positive and CD206-positive （except in the low-dose group） expressions， as well as the protein expressions of iNOS， TLR4， MyD88， NF-κB p65 were all significantly reduced， decreased， shortened， or downregulated， while the protein expression of ARG-1 （except in the low-dose group） was significantly upregulated （ P ＜0.05）. The Jonckheere-Terpstra tests showed that， as the SLKLF dose increased， the levels of IL-10 and TNF-α， the total number of adenomas， the average longest diameter， CD86-positive and CD206-positive expressions， and the protein expression of MyD88 in mice all showed a decreasing trend， while the protein expression of ARG-1 showed an increasing trend （ P ＜0.05）.CONCLUSIONS SLKLF can reduce the CRA burden in Apc Min/+ mice and improve histopathological changes in the adenomas. Its therapeutic effects are accompanied by changes in the expression of proteins associated with the TLR4/MyD88/NF-κB pathway， inflammatory factors， and markers related to macrophage polarization.

Objective:To investigate the application of the conjugate gradient (CG) algorithm to treatment plan optimization for intensity-modulated brachytherapy (IMBT).Methods:The general Monte Carlo software TOPAS was utilized to simulate the 192Ir source of IMBT, and the unit dose contribution matrix was calculated. An objective function was established using the weighted least squares method and was solved using the CG algorithm to achieve optimized IMBT treatment plans. The optimization was validated using five clinical cervical cancer cases under modulation width 60°. The dose distributions of IMBT treatment plans under 45°, 60°, 90°, 120°, and 180° modulation widths were compared using the Wilcoxon test to determine the optimal IMBT treatment plan for cervical cancer treatment. Results:The CG algorithm successfully optimized IMBT treatment plans under modulation width 60° for five cases within 22.2 s on average. On the premise of sufficient target dose coverage, the average D2 cm 3 values of the bladder and rectum in IMBT treatment plans were 3.66 and 1.97 Gy, respectively, representing reductions of 0.54 and 0.69 Gy compared to traditional brachytherapy plans. For the five modulation widths, the D90% values of all IMBT treatment plans reached 6 Gy, without statistically significant differences ( P > 0.05). The average D2 cm 3 values of the bladder in IMBT treatment plans were significantly lower than those in the traditional brachytherapy plans( P<0.05), with modulation width 60° associated with the greatest reduction of 0.61 Gy. In contrast, the average D2 cm 3 values of the rectum under 45°, 60°, and 90° modulation widths decreased by 0.63, 0.54, and 0.45 Gy, respectively, compared to traditional plans, with statistically significant differences( P<0.05). Conclusions:The CG method enables rapid achievement of optimized IMBT treatment plans that meet clinical requirements, and modulation width 60° contributes to valid dosimetric optimization. This study can serve as a guide for the clinical implementation of IMBT.

Objective:To analyze the short-term efficacy and safety of robot-assisted laparoscopic partial nephrectomy（RAPN）for non-metastatic pathological stage T 3a renal cell carcinoma. Methods:The clinical and pathological data of 45 patients with pathologically confirmed non-metastatic T 3a renal cell carcinoma who underwent RAPN at Sun Yat-sen University Cancer Center between January 2016 and December 2023 were retrospectively reviewed. There were 30 males and 15 females. The average age of the cohort was（54.3±10.7）years，and the average clinical tumor diameter was（4.9±1.8）cm. Of all the patients，35（77.8%）were asymptomatic，7（15.6%）presented with hematuria，and 3（6.7%）presented with lumbar pain. Preoperative imaging assessed 34 patients（75.6%）as having clinical stage T 3a，all suspected of involving the collecting system or perirenal fat invasion；the remaining 11 patients（24.4%）were assessed as having stage T 1-2 disease. The median R.E.N.A.L. nephrectomy score was 8.0（7.0，10.0）. A history of hypertension，diabetes，or chronic kidney disease was present in 18 patients（40.0%）. The primary endpoint was progression-free survival，and the secondary endpoints included postoperative complications and short-term renal function outcomes. Survival curve was estimated using the Kaplan-Meier method，and renal function comparisons were made using the paired t-test. Results:The RAPN was performed through a transabdominal approach in 32 patients（71.1%），with a median estimated blood loss of 150.0（50.0，300.0）ml. Seven（15.6%）patients required intraoperative blood transfusion. The median length of postoperative hospital stay was 4.0（4.0，6.0）days. Postoperative complications occurred in 6 patients（13.3%），including 5（11.1%）with mild complications and 1（2.2%）with a severe complication. Renal function returned to baseline in 24 of 39 evaluable patients（61.5%），while 3 patients（7.7%）developed surgery-related chronic kidney disease 3 to 12 months postoperatively，but none required dialysis. The median follow-up time was 31.8（22.7，50.9）months，12（26.7%）patients received programmed cell death protein 1 inhibitor adjuvant therapy postoperatively. During follow-up，3 patients experienced tumor recurrence，the 3-year progression-free survival rate of the entire cohort was 95.4%.Conclusions:For some carefully selected patients with T 3a renal cell carcinoma，RAPN performed by experienced surgeons is a feasible and safe option，providing excellent short-term oncological outcomes，complication control，and renal function recovery. The long-term efficacy remains to be seen.

Objective:To rapidly and accurately detect volumetric modulated arc therapy (VMAT) plans with potentially inaccurate radiation doses.Methods:The measurement-based dosimetric verification result of 196 VMAT plans obtained using ArcCHECK phantoms were retrospectively collected. Independent dosimetric calculation and verification were conducted for these plans using the ArcherQA system based on a fast Monte Carlo algorithm. The gamma passing rates of dosimetric verification using ArcCHECK phantom and the ArcherQA system were compared, followed by their correlation analysis and linear regression fitting. The ArcherQA system′s gamma passing rate threshold used to detect positive dosimetric verification result obtained using ArcCHECK phantoms, as well as the specificity of the detection, were calculated. Based on this gamma passing rate threshold, another 50 VMAT plans were selected as a test set to assess the ArcherQA system′s ability to detect positive measurement-based dosimetric verification result.Results:The average gamma passing rates for the dosimetric verification of the VMAT plans using the ArcherQA system and ArcCHECK phantoms were 97.28% and 96.57% (3%/3 mm, TH=10%), respectively. Both rates had a correlation coefficient of 0.71 ( P < 0.01) and a linear fitting coefficient of 0.54 ( R2=0.51). When the gamma passing rate for dosimetric verification using ArcCHECK phantoms was set at 90% (3%/2 mm, TH=10%), the gamma passing rate threshold for dosimetric verification using the ArcherQA system should be adjusted to 94.8% to detect all VMAT plans with positive dosimetric verification result obtained using ArcCHECK phantoms, with a specificity of 67.8%. Using this threshold, the ArcherQA system detected all VMAT plans in the test set for which ArcCHECK phantom-based measurement yielded positive dosimetric verification result. Conclusions:By determining an appropriate gamma passing rate threshold, the ArcherQA system can rapidly and accurately detect VMAT plans with potentially inaccurate doses, thus ensuring treatment accuracy and improving work efficiency.