Mass Spectrometry-Driven Discovery of Neuropeptides Mediating Nictation Behavior of Nematodes.

Neuropeptides regulate animal physiology and behavior, making them widely studied targets of functional genetics research. While the field often relies on differential -omics approaches to build hypotheses, no such method exists for neuropeptidomics. It would nonetheless be valuable for studying behaviors suspected to be regulated by neuropeptides, especially when little information is otherwise available. This includes nictation, a phoretic strategy of Caenorhabditis elegans dauers that parallels host-finding strategies of infective juveniles of many pathogenic nematodes. We here developed a targeted peptidomics method for the model organism C. elegans and show that 161 quantified neuropeptides are more abundant in its dauer stage compared with L3 juveniles. Many of these have orthologs in the commercially relevant pathogenic nematode Steinernema carpocapsae, in whose infective juveniles, we identified 126 neuropeptides in total. Through further behavioral genetics experiments, we identify flp-7 and flp-11 as novel regulators of nictation. Our work advances knowledge on the genetics of nictation behavior and adds comparative neuropeptidomics as a tool to functional genetics workflows.

A real-world cohort study of first-line afatinib in patients with EGFR-mutant advanced non-small cell lung cancer in Vietnam.

BACKGROUND: This study aimed to evaluate the efficacy and side effects of first-line afatinib treatment in a real-world setting in Vietnam. METHODS: This retrospective study was conducted across nine hospitals in Vietnam. Advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients who received afatinib as first-line therapy between April 2018 and June 2022 were included, and patient medical records were reviewed. Key outcomes were overall response rate (ORR), time-to-treatment failure (TTF), and tolerability. RESULTS: A total of 343 patients on first-line afatinib were eligible for the study. EGFR exon 19 deletion (Del19) alone was detected in 46.9% of patients, L858R mutation alone in 26.3%, and other uncommon EGFR mutations, including compound mutations, in 26.8%. Patients with brain metastases at baseline were 25.4%. Patients who received 40 mg, 30 mg, and 20 mg as starting doses of afatinib were 58.6%, 39.9%, and 1.5%, respectively. The ORR was 78.1% in the overall population, 82.6% in the Del19 mutation subgroup, 73.3% in the L858R mutation subgroup, and 75.0% in the uncommon mutation subgroup (p > 0.05). The univariate and multivariate analyses indicate that the ORR increased when the starting dose was 40 mg compared to starting doses below 40 mg (83.9% vs. 74.3%, p = 0.034). The median TTF (mTTF) was 16.7 months (CI 95%: 14.8-18.5) in all patients, with a median follow-up time of 26.2 months. The mTTF was longer in patients in the common EGFR mutation subgroup (Del19/L858R) than in those in the uncommon mutation subgroup (17.5 vs. 13.8 months, p = 0.045) and in those without versus with brain metastases at baseline (17.5 vs. 15.1 months, p = 0.049). There were no significant differences in the mTTF between subgroups based on the starting dose of 40 mg and < 40 mg (16.7 vs. 16.9 months, p > 0.05). The most common treatment-related adverse events (any grade/grade ≥ 3) were diarrhea (55.4%/3.5%), rash (51.9%/3.2%), paronychia (35.3%/5.0%), and stomatitis (22.2%/1.2%). CONCLUSIONS: Afatinib demonstrated clinical effectiveness and good tolerability in Vietnamese EGFR-mutant NSCLC patients. In our real-world setting, administering a starting dose below 40 mg might result in a reduction in ORR; however, it might not have a significant impact on TTF.

Cardiovascular disease risk assessment and multidisciplinary care in prostate cancer treatment with ADT: recommendations from the APMA PCCV expert network.

PURPOSE: Androgen deprivation therapy (ADT) is the mainstay approach for prostate cancer (PCa) management. However, the most commonly used ADT modality, gonadotropin-releasing hormone (GnRH) agonists, has been associated with an increased risk of cardiovascular disease (CVD). METHODS: The PCa Cardiovascular (PCCV) Expert Network, consisting of multinational urologists, cardiologists and oncologists with expertise in managing PCa, convened to discuss challenges to routine cardiovascular risk assessment in PCa management, as well as how to mitigate such risks in the current treatment landscape. RESULTS: The experts identified several barriers, including lack of awareness, time constraints, challenges in implementing risk assessment tools and difficulties in establishing multidisciplinary teams that include cardiologists. The experts subsequently provided practical recommendations to improve cardio-oncology care for patients with PCa receiving ADT, such as simplifying cardiovascular risk assessment, individualising treatment based on CVD risk categories, establishing multidisciplinary teams and referral networks and fostering active patient engagement. A streamlined cardiovascular risk-stratification tool and a referral/management guide were developed for seamless integration into urologists' practices and presented herein. The PCCV Expert Network agreed that currently available evidence indicates that GnRH antagonists are associated with a lower risk of CVD than that of GnRH agonists and that GnRH antagonists are preferred for patients with PCa and a high CVD risk. CONCLUSION: In summary, this article provides insights and guidance to improve management for patients with PCa undergoing ADT.

Networking community health workers for service integration: role of social media.

Community health workers (CHW) can play an active role in providing integrated HIV and harm reduction services. We used social media to create a virtual network among Vietnamese CHW. This paper reports CHW's social media engagement and the relationships with other work-related indicators. Sixty CHW participated in an intervention for integrated HIV/drug use service delivery. Following two in-person sessions, Facebook groups were established for CHW to share information, seek consultation, and refer patients. CHW's levels of online engagements were tracked for six months and linked to their service provision confidence, interaction with patients and other providers, and job satisfaction. The CHW made 181 posts, which received 557 comments and 1,607 reactions during the six months. Among the 60 CHW, 22 (36.6%) had three or more posts, 19 (31.7%) had one or two posts, and 19 (31.7%) had no post. Comparing the baseline and 6-month follow-up data, we observed that those who posted three or more times showed better service provision confidence (p = 0.0081), more interaction with providers in other settings (p = 0.0071), and higher job satisfaction (p = 0.0268). Our study suggests using social media to engage CHW in virtual communications to improve service provision in communities.

Community Capacity Building for HIV and Addiction Service Integration: An Intervention Trial in Vietnam.

Scientific findings and policy guidelines recommend integrating HIV and drug addiction prevention and care into community-based settings. Systematic capacity-building efforts are warranted to provide technical support for community health workers and improve their confidence in the integrated service provision. An intervention trial was conducted between 2018 and 2019 with 120 community health workers (CHW) from 60 communes in Vietnam's four provinces. The 60 intervention CHW received in-person training to enhance their HIV/addiction-related service knowledge and skills. Online support groups were established between trained CHW and local HIV and addiction specialists. The intervention outcomes were assessed using mixed-effects regression models with the data collected at baseline and every 3 months for 1 year. Adjusted analyses showed that intervention CHW reported a significant increase in the interaction with other treatment providers than the control group at 6 months and remained at the 12-month follow-up. The difference in the improvement of confidence in HIV/addiction-related service delivery between the intervention and control groups was significant at 6-month but became insignificant at the 12-month. Male CHW were more confident in providing services than female CHW at baseline, and gender differences in the changing patterns were observed over time. This capacity-building intervention demonstrated promising outcomes on CHW inter-agency collaborations and confidence in service delivery. Gender divides in healthcare professionals should be attended to in future studies.

RESUMEN: Los hallazgos científicos y los protocolos recomiendan integrar la prevención del VIH y la adicción a las drogas en entornos comunitarios. Se implementan esfuerzos sistemáticos de creación de capacidad para brindar apoyo técnico a los trabajadores de salud comunitarios y mejorar su confianza en la prestación de servicios integrados. Se realizó una prueba de intervención entre 2018 y 2019 con 120 trabajadores de salud comunitarios (TSC) de 60 comunas en las cuatro provincias de Vietnam. Los 60 TSC de intervención recibieron capacitación en persona para mejorar sus conocimientos y habilidades de servicios relacionados con VIH / adicción. Se establecieron grupos de apoyo en línea entre TSC capacitados y especialistas locales en VIH y adicciones. Los resultados de la intervención se evaluaron mediante modelos de regresión de efectos mixtos con los datos recopilados al inicio del estudio y cada tres meses durante un año. Los análisis ajustados mostraron que la intervención CHW informó un aumento significativo en la interacción con proveedores de tratamiento diferentes al grupo de control a los seis meses que se mantuvo en el seguimiento a los 12 meses. La diferencia en el aumento de la confianza en la prestación de servicios relacionados con VIH / adicción entre los grupos de intervención y control fue significativa a los 6 meses, pero se volvió insignificante a los 12 meses. Los TSC masculinos tenían más confianza en la prestación de servicios que las femeninas al inicio del estudio, y se observaron diferencias de género en el cambio de patrones a lo largo del tiempo. Esta intervención de creación de capacidad demostró resultados prometedores en las colaboraciones interinstitucionales de los TSC y la confianza en la prestación de servicios. Las brechas de género en los profesionales de la salud deben ser atendidas en estudios futuros.

Essential Oils of Polyalthia suberosa Leaf and Twig and Their Cytotoxic and Antimicrobial Activities.

Essential oils from the leaf and twig of Polyalthia suberosa (Roxb.) Thwaites were analyzed using GC/MS/FID. A total of sixty-three constituents were namely identified accounting for 96.03 and 94.12 % in the hydrodistilled oils of the leaf and twig, respectively. Monoterpenes, monoterpenoids, sesquiterpenes, and sesquiterpenoids were characteristic derivatives of P. suberosa essential oils. Sesquiterpenes bicyclogermacrene (26.26 %) and (E)-caryophyllene (7.79 %), and monoterpene ß-pinene (12.71 %) were the major constituents of the leaf oil. Sesquiterpenes (E)-caryophyllene (17.17 %) and α-humulene (9.55 %), sesquiterpenoid caryophyllene oxide (9.41 %), and monoterpenes camphene (8.16 %) and tricyclene (6.35 %) were to be main components in the twig oil. The leaf oil indicated cytotoxic activity against three cancer cell lines HepG2, MCF7 and A549 with the IC50 values of 60.96-69.93 µg/mL, while the twig oil inhibited MCF7 with the IC50 value of 66.70 µg/mL. Additionally, the twig oil successfully suppressed the growth of the negative Gram bacterium Pseudomonas aeruginosa, fungus Aspergillus niger, and yeast Candida albicans with the same MIC value of 50 µg/mL, whereas the leaf oil had the same result on the negative Gram bacterium Escherichia coli.

Theoretical Analysis for Using Pulsed Heating Power in Magnetic Hyperthermia Therapy of Breast Cancer.

In magnetic hyperthermia, magnetic nanoparticles (MNPs) are used to generate heat in an alternating magnetic field to destroy cancerous cells. This field can be continuous or pulsed. Although a large amount of research has been devoted to studying the efficiency and side effects of continuous fields, little attention has been paid to the use of pulsed fields. In this simulation study, Fourier's law and COMSOL software have been utilized to identify the heating power necessary for treating breast cancer under blood flow and metabolism to obtain the optimized condition among the pulsed powers for thermal ablation. The results showed that for small source diameters (not larger than 4 mm), pulsed powers with high duties were more effective than continuous power. Although by increasing the source domain the fraction of damage caused by continuous power reached the damage caused by the pulsed powers, it affected the healthy tissues more (at least two times greater) than the pulsed powers. Pulsed powers with high duty (0.8 and 0.9) showed the optimized condition and the results have been explained based on the Arrhenius equation. Utilizing the pulsed powers for breast cancer treatment can potentially be an efficient approach for treating breast tumors due to requiring lower heating power and minimizing side effects to the healthy tissues.

Magnetization Dynamics on Isotope-Isomorphic Holmium Single-Molecule Magnets.

Here we reported the deuteration of the metal-binding equatorial water molecules in a reported HoIII single-molecule magnet (SMM) with pentagonal-bipyramidal geometry, from [Ho(CyPh2 PO)2 (H2 O)5 ]3+ to [Ho(CyPh2 PO)2 (D2 O)5 ]3+ . The hyperfine structures originating from the nuclear spin of 165 HoIII can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope-isomorphic complexes-respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the ab initio calculated tunnel splitting and the involvement of the super-hyperfine interaction related to the difference in the nuclear spin number of protium (1 H, I=1 /2 ) and deuterium (2 H, I=1).

Molecular typing of conjunctivitis-causing adenoviruses in Hanoi, Vietnam from 2017 to 2019 and complete genome analysis of the most prevalent type (HAdV-8).

Adenoviral conjunctivitis is a common epidemic worldwide. In Vietnam, up to 80,000 patients are infected with adenoviral conjunctivitis annually. However, there are few investigations on the pathogenic adenoviruses that cause conjunctivitis. In total, 120 eye-swab samples were collected from patients with viral conjunctivitis symptoms in Hanoi, Vietnam from 2017 to 2019. Human adenoviruse (HAdV) was detected in 67 samples (55.83%) using polymerase chain reaction amplification of at least one of three HAdV-specific marker genes (hexon, penton, and fiber). Of the 67 HAdV samples, 46 samples could be analyzed by all three marker genes. DNA sequence analysis and phylogenetic tree building based on the three marker genes from the 46 HAdV samples revealed five different HAdV types associated with conjunctivitis in Hanoi, including HAdV-3 (4.3%), HAdV-4 (2.2%), HAdV-8 (89.1%), HAdV-37 (2.2%), and a potential recombinant type between types HAdV-8 and HAdV-3 (2.2%). This showed that HAdV-8 was the most common type identified in Hanoi. Complete genome analysis of HAdV-8 isolated from a Vietnamese patient (VN2017) using Sanger sequencing revealed 34 unique nucleotide changes, indicating that the adenovirus continuously accumulates new mutations. Hence, continuous surveillance of HAdV-8 changes in Vietnam is necessary in the future.

Preferences for methadone clinics among drug users in Vietnam: a comparison between public and private models.

BACKGROUND: Methadone maintenance treatment (MMT) has been proven to be effective in treating opioid dependence. In Vietnam, MMT services are provided primarily by public clinics, with only one private MMT clinic established in recent years. Assessing the preferences of patients for different MMT models is important in evaluating the feasibility of these models. This study measured the preferences of drug users enrolling in public and private MMT clinics in Vietnam and examines the related factors of these preferences. METHODS: A cross-sectional study was performed on 395 participants at 3 methadone clinics in Nam Dinh. Data about the preferences for MMT models and sociodemographic characteristics of participants were collected. Exploratory factor analysis was employed to explore the construct validity of the questionnaire. The chi-square test and Mann-Whitney test were used for analyzing demographic characteristics and preferences of participants. Multivariate logistic regression identified factors associated with participants' preferences. RESULTS: Half the participants received MMT treatment in a private facility (49.4%). Two preference dimensions were defined as "Availability and convenience of service" and "Competencies of clinic and health professionals". Self-employed patients were more likely to consider these two dimensions when choosing MMT models. Only 9.9% of participants chose "Privacy" as one of the evaluation criteria for an MMT facility. Compared to public clinics, a statistically higher percentage of patients in the private clinic chose the attitudes of health workers as the reason for using MMT service (34.7% and 7.6% respectively). Mean score of satisfaction towards MMT services was 8.6 (SD = 1.0), and this score was statistically higher in a public facility, compared to the private facility (8.7 and 8.4 respectively). CONCLUSIONS: The study highlighted patterns of patient preferences towards MMT clinics. Compared to the public MMT model, the private MMT model may need to enhance their services to improve patient satisfaction.

Pushing the Scalability of RDF Engines on IoT Edge Devices.

Semantic interoperability for the Internet of Things (IoT) is enabled by standards and technologies from the Semantic Web. As recent research suggests a move towards decentralised IoT architectures, we have investigated the scalability and robustness of RDF (Resource Description Framework)engines that can be embedded throughout the architecture, in particular at edge nodes. RDF processing at the edge facilitates the deployment of semantic integration gateways closer to low-level devices. Our focus is on how to enable scalable and robust RDF engines that can operate on lightweight devices. In this paper, we have first carried out an empirical study of the scalability and behaviour of solutions for RDF data management on standard computing hardware that have been ported to run on lightweight devices at the network edge. The findings of our study shows that these RDF store solutions have several shortcomings on commodity ARM (Advanced RISC Machine) boards that are representative of IoT edge node hardware. Consequently, this has inspired us to introduce a lightweight RDF engine, which comprises an RDF storage and a SPARQL processor for lightweight edge devices, called RDF4Led. RDF4Led follows the RISC-style (Reduce Instruction Set Computer) design philosophy. The design constitutes a flash-aware storage structure, an indexing scheme, an alternative buffer management technique and a low-memory-footprint join algorithm that demonstrates improved scalability and robustness over competing solutions. With a significantly smaller memory footprint, we show that RDF4Led can handle 2 to 5 times more data than popular RDF engines such as Jena TDB (Tuple Database) and RDF4J, while consuming the same amount of memory. In particular, RDF4Led requires 10%-30% memory of its competitors to operate on datasets of up to 50 million triples. On memory-constrained ARM boards, it can perform faster updates and can scale better than Jena TDB and Virtuoso. Furthermore, we demonstrate considerably faster query operations than Jena TDB and RDF4J.

Using Social Media to Enhance Provider Network for HIV and Harm Reduction Service Integration in Vietnam.

Social media can potentially serve as a platform to coordinate medical care among fragmented health sectors. This paper describes procedures of using social media to enhance antiretroviral therapy (ART) and methadone maintenance treatment (MMT) providers' virtual network for integrated service for HIV-positive people who inject drugs (PWID) in Vietnam. A total of 88 ART and MMT treatment providers participated in person group sessions followed by online virtual support to improve service integration. In-person reunions were held to reinforce Facebook participation and network activities. Content analysis was used to identify keywords and topic categories of the online information exchange. Both MMT and ART providers were actively engaged in online communications. Referral and treatment adherence were the two most frequently discussed topic areas by both the MMT and ART providers. Frequent cross-agency connections were observed. Online provider networks and communities could be built and useful to support treatment providers to improve service integration.

Theoretical Analysis for Wireless Magnetothermal Deep Brain Stimulation Using Commercial Nanoparticles.

A wireless magnetothermal stimulation (WMS) is suggested as a fast, tetherless, and implanted device-free stimulation method using low-radio frequency (100 kHz to 1 MHz) alternating magnetic fields (AMF). As magnetic nanoparticles (MNPs) can transduce alternating magnetic fields into heat, they are targeted to a region of the brain expressing the temperature-sensitive ion channel (TRPV1). The local temperature of the targeted area is increased up to 44 °C to open the TRPV1 channels and cause an influx of Ca2+ sensitive promoter, which can activate individual neurons inside the brain. The WMS has initially succeeded in showing the potential of thermomagnetics for the remote control of neural cell activity with MNPs that are internally targeted to the brain. In this paper, by using the steady-state temperature rise defined by Fourier's law, the bio-heat equation, and COMSOL Multiphysics software, we investigate most of the basic parameters such as the specific loss power (SLP) of MNPs, the injection volume of magnetic fluid, stimulation and cooling times, and cytotoxic effects at high temperatures (43-44 °C) to provide a realizable design guideline for WMS.

Synthesis of 1-(para-methoxyphenyl)tetrazolyl-Substituted 1,2,3,4-Tetrahydroisoquinolines and Their Transformations Involving Activated Alkynes.

1-(p-Methoxyphenyl)tetrazolyl-substituted 6,7-dimethoxy(6,7-methylenedioxy)-1,2,3,4-tetrahydroisoquinolines formed tetrazolyl-substituted azocines in high yields by using activated alkynes. Unsubstituted at 6,7,8-aromatic fragment 1-tetrazolylisoquinoline interacted in several pathways forming tetrazolyl-substituted azocines, 1-tetrazolyl-1-R-vinylisoquinolines and 3-azaspiro[5.5]undeca-1,7,9-triene.

Real-Time Two-Dimensional Magnetic Particle Imaging for Electromagnetic Navigation in Targeted Drug Delivery.

Magnetic nanoparticles (MNPs) are effective drug carriers. By using electromagnetic actuated systems, MNPs can be controlled noninvasively in a vascular network for targeted drug delivery (TDD). Although drugs can reach their target location through capturing schemes of MNPs by permanent magnets, drugs delivered to non-target regions can affect healthy tissues and cause undesirable side effects. Real-time monitoring of MNPs can improve the targeting efficiency of TDD systems. In this paper, a two-dimensional (2D) real-time monitoring scheme has been developed for an MNP guidance system. Resovist particles 45 to 65 nm in diameter (5 nm core) can be monitored in real-time (update rate = 2 Hz) in 2D. The proposed 2D monitoring system allows dynamic tracking of MNPs during TDD and renders magnetic particle imaging-based navigation more feasible.

A simple derivation of the Landau-Zener formula.

Using the contour integration approach proposed earlier, we find a simple derivation of the Landau-Zener formula which does not use explicitly the solution of the Schrödinger equation.

Fabrication of ZnO nanorods for gas sensing applications using hydrothermal method.

We showed well-aligned zinc oxide (ZnO) nanorod arrays synthesized using hydrothermal method at atmospheric pressure. The influence of fabrication conditions such as Zn2+/hexamethylentriamin concentration ratio, and growth temperature on the formation of ZnO nanorods was investigated. Scanning Electron Microscope (SEM) images and X-ray Diffraction (XRD) analysis were used to confirm the single crystal of ZnO nanorods, which showed wurtzite structure with growth direction of [0001] (the c-axis). Photoluminescence (PL) measurements of ZnO nanorods revealed an intense ultraviolet peak at 388.5 nm (3.19 eV) at room temperature. The results showed that the ZnO seed layers had strong influence on the growth of vertically aligned ZnO nanorods. The gas sensor based on ZnO nanorod arrays had the most selectivity with n-butanol gas (within 2 surveyed gas: ethanol and n-butanol) and showed a higher sensitivity of 222, fast response time of 15 seconds, recovery time of 110 seconds and lower operating temperature of 200-250 °C than the sensor based on the ZnO film in the same detecting conditions.

Magnetic particle image scanner based on asymmetric core-filled electromagnetic actuator.

Monitoring the distribution of magnetic nanoparticles (MNPs) in the vascular system is an important task for the advancement of precision therapeutics and drug delivery. Despite active targeting using active motilities, it is required to visualize the position and concentration of carriers that reach the target, to promote the development of this technology. In this work, a feasibility study is presented on a tomographic scanner that allows monitoring of the injected carriers quantitatively in a relatively short interval. The device is based on a small-animal-scale asymmetric magnetic platform integrated with magnetic particle imaging technology. An optimized isotropic field-free region (FFR) generation method using a magnetic manipulation system (MMS) is derived and numerically investigated. The in-vitro and in-vivo tracking performances are demonstrated with a high position accuracy of approximately 1 mm. A newly proposed tracking method was developed, specialized in vascular system, with quick scanning time (about 1s). In this paper, the primary function of the proposed system is to track magnetic particles using a magnetic manipulation system. Through this, proposed method enables the conventional magnetic actuation systems to upgrade the functionalities of both manipulation and localization of magnetic objects.

Towards human-scale magnetic particle imaging: development of the first system with superconductor-based selection coils.

Magnetic Particle Imaging (MPI) is an emerging tomographic modality that allows for precise three-dimensional (3D) mapping of magnetic nanoparticles (MNPs) concentration and distribution. Although significant progress has been made towards improving MPI since its introduction, scaling it up for human applications has proven challenging. High-quality images have been obtained in animal-scale MPI scanners with gradients up to 7 T/m/µ0, however, for MPI systems with bore diameters around 200 mm the gradients generated by electromagnets drop significantly to below 0.5 T/m/µ0. Given the current technological limitations in image reconstruction and the properties of available MNPs, these low gradients inherently impose limitations on improving MPI resolution for higher precision medical imaging. Utilizing superconductors stands out as a promising approach for developing a human-scale MPI system. In this study, we introduce, for the first time, a human-scale amplitude-modulated (AM) MPI system with superconductor-based selection coils. The system achieves an unprecedented magnetic field gradient of up to 2.5 T/m/µ0 within a 200 mm bore diameter, enabling large fields of view of 100 × 130 × 98 mm3 at 2.5 T/m/µ0 for 3D imaging. While obtained spatial resolution is in the order of previous animal-scale AM MPIs, incorporating superconductors for achieving such high gradients in a 200 mm bore diameter marks a major step toward clinical MPI.

Synthesis and crystal structure of the adduct between 2-pyridyl-selenyl chloride and isobutyro-nitrile.

The reaction between 2-pyridyl-selenenyl chloride and isobutyro-nitrile results in the formation of the corresponding cationic pyridinium-fused 1,2,4-seleno-diazole, namely, 3-(propan-2-yl)-1,2,4-[1,2,4]selena-diazolo[4,5-a]pyridin-4-ylium chloride, C9H11N2Se+·Cl-, in high yield (89%). The structure of the compound, established by means of single-crystal X-ray analysis at 100 K, has monoclinic (P21/c) symmetry and revealed the presence of bifurcated chalcogen-hydrogen bonding Se⋯Cl-⋯H-Cl, and these non-covalent contacts were analysed by DFT calculations followed by a topological analysis of the electron-density distribution (ωB97XD/6-311++G** level of theory).