4-Point scleral fixation technique using Gore-tex® sutures for cut-out plated haptic intraocular lenses.

Purpose: To report a 4-point scleral fixation technique utilizing Gore-tex® CV8 sutures and cut-out plated haptic intraocular lenses (IOLs) lacking a 4-eyelet haptic design for aphakic patients. Observations: This scleral fixation technique utilizes Gore-tex CV8® sutures paired with a foldable, monofocal, cut-out plated haptic IOLs wherein the sutures are passed through the holes of the plate haptics. Initially, sectoral conjunctival peritomies are performed on the temporal and medial conjunctiva. This is followed by the creation of 4 sclerotomy sites 5mm from each other and 2mm from the limbus at the exposed medial and temporal sclera. A Gore-Tex® (CV8) suture is threaded under the plate haptic. The leading suture is then inserted intraocularly through the corneal incision and externalized through the inferior sclerotomy. The trailing end of the suture which is over the haptic plate is passed intraocularly and externalized through the same port. The externalized suture is brought back intraocularly through the superior sclerotomy and then re-externalized through the corneal incision. This suture end is then threaded through the superior portion of the plate haptic in an over-under fashion. The suture which has passed under the haptic plate, is then brought back intraocularly through the corneal incision and externalized through the superior sclerotomy creating a loop. The same steps are then performed on the contralateral side. The IOL is then inserted. Centration of the IOL is then achieved by adjusting the tension on the 4 externalized suture ends. The Gore-Tex® sutures are then tied and subsequently buried into the sclerotomy. Conjunctival peritomies are then repaired. Conclusions and importance: Four-point fixation of cut-out plate haptic IOLs is achievable with predictable outcomes showing good centration, stability, visual and refractive outcomes providing surgeons additional options for fixation of available lenses as a secondary or primary implantation or by fixation of subluxed or dropped plate IOLs.

Effect of 4-Ethylbenzaldehyde from the Volatilome of Annona muricata on Meloidogyne incognita.

The demand for new soil fumigants has increased as a result of more restrictive legislation regarding the use of pesticides. In the present study, the potent nematicidal activity of volatile organic compounds released by the Annona muricata leaf macerate was demonstrated. In addition, we searched in the A. muricata volatilome for a molecule with potential to be developed as a new fumigant nematicide. In the greenhouse, even the lowest concentration of soursop leaf macerate tested (1.0%) as a biofumigant caused a significant (P < 0.05) reduction in Meloidogyne incognita infectivity and reproduction when compared with the nontreated control (0%). Forty-one compounds were identified through gas chromatography-mass spectrometry analysis, of which three (sabinene, caryophyllene oxide, and 4-ethylbenzaldehyde) were selected for studies against the nematode. Among these compounds, in in vitro trails, only 4-ethylbenzaldehyde showed nematicidal activity at 250 µg ml-1. The effective doses of 4-ethylbenzaldehyde predicted to kill 50 and 95% of the M. incognita second-stage juvenile population after 48 h of exposure were 35 and 88 µg ml-1, respectively. In in vitro tests, 4-ethylbenzaldehyde at 150 µg ml-1 reduced M. incognita egg hatching to values similar (P > 0.05) to those of the commercial nematicide fluensulfone at a concentration of 200 µg ml-1. In plant experiments, as a soil fumigant, 4-ethylbenzaldehyde at a dose of 1 ml/liter of substrate had an effect similar (P > 0.05) to that of the commercial fumigant Dazomet (250 µg ml-1). Therefore, 4-ethylbenzaldehyde shows potential for development as a new nematicide.

Influence of different recovery intervals on time under tension, total training volume, and fatigue index in horizontal bench press exercise in young male wrestling athletes.

BACKGROUND: The recovery interval (RI) seems to be a variable closely related to the training volume since it can determine the performance after this rest time. This study investigated the influence of different recovery intervals on time under tension (TUT), total training volume (TTV), and Fatigue Index (FI) in the horizontal bench press exercise. METHODS: Eighteen male wrestling athletes underwent three visits: 1st) performed the 10-repetition maximum (10RM) test; 2nd and 3rd) performed 5 sets of up to 10 repetitions with 1 minute (RI1) and 3 minutes (RI3) of passive RI with randomized entry. TUT, number of repetitions, TTV and FI data were collected or calculated. RESULTS: TUT was lower in sets 5 (P<0.001) for RI1 when compared to RI3, with no significant difference for the other 4 sets. The number of repetitions for RI1 was lower when compared to RI3 in sets 3 (P=0.018), 4 (P=0.023), and 5 (P<0.001), with no significant difference in sets 1 and 2. The FI was significantly higher for RI1 (P<0.001); however, TTV was significantly higher for RI3 (P=0.007). CONCLUSIONS: Different RI influenced the TUT and the number of repetitions along 5 sets in the horizontal bench press exercise. Moreover, these two variables showed different behavior when compared under the same condition (RI1 or RI3), especially after the third set. Using longer RI demonstrated a greater ability to maintain TTV and less negative effect of fatigue in young male wrestling athletes.

Unilateral perineal hernia surgery. Case report / Cirugía unilateral de hernia perineal. Reporte de caso

ABSTRACT Perineal hernia results from weakening and/or the inability of the pelvic diaphragm to support the rectal wall, promoting caudal displacement of abdominal or pelvic organs in the perineum. Unneutered male dogs aged between 7 and 10 years are the most affected, being rare in females. The main clinical signs are unilateral or bilateral swelling of the perineal region, associated or not with tenesmus, dysuria, urinary and/or fecal incontinence, anuria and pain during defecation. The diagnosis is based on clinical history, anamnesis, physical examination, and complementary tests such as radiography and ultrasound. Clinical treatment can be done in some cases, but surgical intervention is required to resolve the problem. The present work aims to report the case of a patient treated at the FullPet Veterinary Clinic in Guarulhos, São Paulo, Brazil, a 7-year-old male Yorkshire canine, unneutered, weighing 4.5 kg. The same was submitted to surgery by the traditional method of suture with nylon thread and enteropexy. When there was recurrence, surgical reintervention was necessary to correct the hernia using a polypropylene mesh.

RESUMEN La hernia perineal resulta del debilitamiento y/o incapacidad del diafragma pélvico para sostener la pared rectal, lo que promueve el desplazamiento caudal de los órganos abdominales o pélvicos en el perineo. Los perros machos no castrados de entre 7 y 10 años son los más afectados, siendo raro en las hembras. Los principales signos clínicos son tumefacción unilateral o bilateral de la región perineal, asociada o no a tenesmo, disuria, incontinencia urinaria y/o fecal, anuria y dolor durante la defecación. El diagnóstico se basa en la historia clínica, la anamnesis, el examen físico y pruebas complementarias como la radiografía simple y la ecografía. El tratamiento clínico se puede hacer en algunos casos, pero se requiere una intervención quirúrgica para resolver el problema. El presente trabajo tiene como objetivo relatar el caso de un paciente atendido en la Clínica Veterinaria FullPet de Guarulhos, São Paulo, Brasil, un canino Yorkshire macho de 7 años, sin castrar, con un peso de 4,5 kg. Fue intervenido quirúrgicamente por el método tradicional de sutura con hilo de nylon y enteropexia. Cuando hubo recidiva, fue necesaria la reintervención quirúrgica para corregir la hernia mediante una malla de polipropileno.

Influenza vaccination strategy in acute coronary syndromes: the VIP-ACS trial.

AIMS: To evaluate whether a strategy of double-dose influenza vaccination during hospitalization for an acute coronary syndrome (ACS) compared with standard-dose outpatient vaccination (as recommended by current guidelines) would further reduce the risk of major cardiopulmonary events. METHODS AND RESULTS: Vaccination against Influenza to Prevent cardiovascular events after Acute Coronary Syndromes (VIP-ACS) was a pragmatic, randomized, multicentre, active-comparator, open-label trial with blinded outcome adjudication comparing two strategies of influenza vaccination following an ACS: double-dose quadrivalent inactivated vaccine before hospital discharge vs. standard-dose quadrivalent inactivated vaccine administered in the outpatient setting 30 days after randomization. The primary outcome was a hierarchical composite of all-cause death, myocardial infarction, stroke, unstable angina, hospitalization for heart failure, urgent coronary revascularization, and hospitalization for respiratory causes, analysed by the win ratio method. Patients were followed for 12 months. During two influenza seasons, 1801 participants were included at 25 centres in Brazil. The primary outcome was not different between groups, with 12.7% wins in-hospital double-dose vaccine group and 12.3% wins in the standard-dose vaccine group {win ratio: 1.02 [95% confidence interval (CI): 0.79-1.32], P = 0.84}. Results were consistent for the key secondary outcome, a hierarchical composite of cardiovascular death, myocardial infarction and stroke [win ratio: 0.94 (95% CI: 0.66-1.33), P = 0.72]. Time-to-first event analysis for the primary outcome showed results similar to those of the main analysis [hazard ratio 0.97 (95% CI: 0.75-1.24), P = 0.79]. Adverse events were infrequent and did not differ between groups. CONCLUSION: Among patients hospitalized with an ACS, double-dose influenza vaccination before discharge did not reduce cardiopulmonary outcomes compared with standard-dose vaccination in the outpatient setting. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov number: NCT04001504.

(R)-Carvone is a potential soil fumigant against Meloidogyne incognita whose likely enzymatic target in the nematode is acetylcholinesterase.

To contribute to the development of new fumigant nematicides for the control of the plant-parasitic nematode Meloidogyne incognita, this study started with 31 volatile organic compounds reported as toxic to nematodes. At 500 µg/mL, α-ionone, (S)-carvone, (R)-carvone, 2-methylpropyl acetate, undecan-2-one, decan-2-one, and dodecan-2-one caused mortalities to M. incognita second-stage juveniles (J2) that were similar to those obtained with the commercial nematicides carbofuran (170 µg/mL) and fluensulfone (42.2 µg/mL). (R)-carvone, with a lethal concentration to 50% J2 (LC50) equal to 524 µg/mL, was selected for subsequent studies. When J2 were exposed to the (R)-carvone solution, the infectivity and reproduction on tomato were reduced. In the M. incognita egg hatching assay, (R)-carvone behaved like a true ovicide. When employed as a fumigant, (R)-carvone (3.9 g/L) was as efficient as the soil fumigant dazomet (0.245 g/L) in eliminating eggs of the nematode in a substrate to be used for tomato planting. According to in silico studies employing pharmacophoric searches and molecular docking, acetylcholinesterases are the target of (R)-carvone in the nematode.

A Polypyrrole/Nanoclay Hybrid Film for Ultra-Sensitive Cardiac Troponin T Electrochemical Immunosensor.

An electrochemical immunosensor based on a nanohybrid film of carboxylated polypyrrole and amine nanoclay was developed for label-free detection of the human cardiac troponin T (cTnT). The nanohybrid film was formed in situ on the surface of the glassy carbon electrode, followed by the covalent immobilization of anti-troponin T antibodies by glutaraldehyde. Morphological and chemical characterizations of the nanohybrid film were performed by scanning electron microscopy and Fourier-transform infrared spectroscopy. Under the optimized conditions, a calibration curve for cTnT in spiked serum was obtained by square wave voltammetry, and a low limit of detection and quantification was achieved (0.35 and 1.05 pg mL-1, respectively). This was the first time that this type of nanohybrid film was used in the development of an immunosensor for cTnT that proved to be a simple and efficient strategy for the manufacture of a label-free electrochemical device that could be applied in the diagnosis of acute myocardial infarction.

Temperature Effects on Development of Meloidogyne Enterolobii and M. Floridensis.

Meloidogyne enterolobii and M. floridensis are virulent species that can overcome root-knot nematode resistance in economically important crops. Our objectives were to determine the effects of temperature on the infectivity of second-stage juveniles (J2) of these two species and determine differences in duration and thermal-time requirements (degree-days [DD]) to complete their developmental cycle. Florida isolates of M. enterolobii and M. floridensis were compared to M. incognita race 3. Tomato cv. BHN 589 seedlings following inoculation were placed in growth chambers set at constant temperatures of 25°C, and 30°C, and alternating temperatures of 30°C to 25°C (day-night). Root infection by the three nematode species was higher at 30°C than at 25°C, and intermediate at 30°C to 25°C, with 33%, 15%, and 24% infection rates, respectively. There was no difference, however, in the percentages of J2 that infected roots among species at each temperature. Developmental time from infective J2 to reproductive stage for the three species was shorter at 30°C than at 25°C, and 30°C to 25°C. The shortest time and DD to egg production for the three species were 13 days after inoculation (DAI) and 285.7 DD, respectively. During the experimental timeframe of 29 d, a single generation was completed at 30°C for all three species, whereas only M. floridensis completed a generation at 30°C to 25°C. The number of days and accumulated DD for completing the life cycle (from J2 to J2) were 23 d and 506.9 DD for M. enterolobii, and 25 d and 552.3 DD for M. floridensis and M. incognita, respectively. Exposure to lower (25°C) and intermediate temperatures (30°C to 25°C) decreased root penetration and slowed the developmental cycle of M. enterolobii and M. floridensis compared with 30°C.

Electromyographic analysis of pelvic floor muscles during the execution of pelvic patterns of proprioceptive neuromuscular facilitation-concept: An observational study.

OBJECTIVE: To assess the effect of pelvic patterns of proprioceptive neuromuscular facilitation (PNF-concept) on pelvic floor muscles (PFM) recruitment, as well as the electromyographic activity of muscles synergic to the pelvic floor in healthy women. METHODS: Observational study conducted with 31 women aged between 18 and 35 years, with mean age of 23.3 ± 3.2 (22.1-24.4). PFM activity was monitored by surface electromyography during the combination of isotonics technique of four pelvic patterns of PNF-concept (i.e., anterior elevation, posterior depression, anterior depression, and posterior elevation). The electromyographic signal was analyzed using root mean square amplitude. Two-way repeated measures analysis of variance was performed to analyze differences in PFM activity between types of contraction (i.e., concentric, isometric, and eccentric) and the four pelvic patterns. RESULTS: PFM activity did not differ among the four pelvic pattens. However, PFM activity was significantly different between the combination of isotonics technique and baseline, F(1.6, 48.2) = 71.5; p < 0.000, with a large effect size (partial ƞ² = 0.705). Concentric (22.4 µV ± 1.1), isometric (17.3 µV ± 0.6), and eccentric (15 µV ± 0.5) contractions of combination of isotonics technique increased PFM activity compared with baseline (10.8 µV ± 0.4) in all pelvic patterns. By analyzing the electromyographic activity of the muscles synergistic to the pelvic floor, there is effect of the interaction of the type of contraction, the pelvic pattern of the PNF concept, and the synergistic muscles on the myoelectric activity of the external anal sphincter, F(3.2, 96.5) = 5.6; p < 0.000, with a large magnitude of effect (partial ƞ² = 0.15). In the anterior elevation pattern, the muscles synergistic to the pelvic floor present synergy in phase with the PFM, and in the posterior patterns there was a decrease in the activity level of all synergistic muscles, without changing the activity level of the PFM. CONCLUSION: PFM activity did not differ among the four pelvic patterns of PNF-concept. Nonetheless, the combination of isotonics technique showed a significant effect on PFM compared with baseline, with greater PFM activity during concentric contraction. Pelvic patterns of PNF-concept may be used to increase PFM recruitment in young healthy women.

Methyl Esters of (E)-Cinnamic Acid: Activity against the Plant-Parasitic Nematode Meloidogyne incognita and In Silico Interaction with Histone Deacetylase.

(E)-Cinnamaldehyde is very active against Meloidogyne incognita but has low persistence in soil. To circumvent this problem, esters of cinnamic acid were evaluated as a substitute for (E)-cinnamaldehyde. The best results under assays with M. incognita second-stage juveniles (J2) were obtained for the methyl esters of (E)-p-fluoro- (13), (E)-p-chloro- (14), and (E)-p-bromocinnamic acid (15), which showed lethal concentrations to 50% (LC50) J2 of 168, 95, and 216 µg/mL, respectively. Under the same conditions, the LC50 values for the nematicides carbofuran and fluensulfone were 160 and 34 µg/mL, respectively. Substances 13-15 were also active against nematode eggs, which account for most of the M. incognita population in the field. According to an in silico study, substances 13-15 can act against the nematode through inhibition of histone deacetylase. Therefore, esters 13-15 and histone deacetylase are potentially useful for the rational design of new nematicides for the control of M. incognita.

Effects of Pilates with and without elastic resistance on health variables in postmenopausal women with low back pain.

Aim: To compare the effects of Pilates with and without accessories on biochemical markers, pain intensity, functional disability and muscle strength in postmenopausal women with nonspecific chronic low back pain. Materials & methods: Twenty-two participants were randomized to a group of Pilates without (PG; n = 11) and with elastic resistance (PAG; n = 11) for 8 weeks, twice a week. We analyzed IGF-1, IGF-binding protein-3 (IGFBP-3), cortisol, creatine kinase, pain intensity, functional disability, abdominal and back strengths. Results: Both groups had lower pain intensity and functional disability and increased lumbar strength postinterventions. PAG exhibited an increase in IGF-1/IGFBP-3 ratio and reduction in creatine kinase compared with PG. Conclusion: Both interventions were effective in the treatment of low back pain. However, PAG presented better responses than PG. Clinical Trial Registration: Brazilian Clinical Trials Registry: ReBEC (RBR-9jwcykc), www.ensaiosclinicos.gov.br/rg/RBR-9jwcykc.

Pilates is a type of exercise that has been practiced, both in health promotion and rehabilitation, including low back pain (LBP) treatment. LBP prevails in women after menopause when compared with men. Thus, we submitted postmenopausal women with chronic LBP to two groups, one that practiced Pilates with elastic resistance and the other without these accessories. These elastic bands of progressive tension increase the effort of the exercise performed. We analyzed biochemical markers, pain intensity, functional disability and muscle strength. After 8 weeks, both groups had lower pain intensity and functional disability and increased lumbar strength. Furthermore, the group that used elastic resistance during the training showed increase in IGF-1/IGFBP-3 ratio and reduction in creatine kinase compared with the other group.

[Psychometric evaluation of breastfeeding self efficiency scale in chilean sample]. / Evaluación psicométrica de la escala de autoeficacia de la lactancia materna, en una muestra chilena.

Breastfeeding self-efficacy is one of the indicators associated with the mental health of puerperal women and the maintenance of exclusive breastfeeding. OBJECTIVE: To evaluate the psychometric properties of an instrument to measure self-efficacy to breastfeed on the second postpartum day in the Chilean population. SUBJECTS AND METHOD: A convenience sample of 320 puerperal women who volunteered to participate in an interview on their second postpartum day was evaluated. Reliability was evaluated using the coefficient Cronbach's alpha. To assess its factorial structure, an exploratory factor analysis was performed. RESULTS: The results indicate that the final instrument, which has the factors "Intrapersonal Thoughts", composed of six items and "Breastfeeding Techniques", composed of eight items, presented an internal consistency by factor and total scale of F1 = 0.90, F2 = 0.91, and Total = 0.94, respectively. CONCLUSION: The breastfeeding self-efficacy scale showed good psychome tric characteristics during the second postpartum day among Chilean puerperal women.

The combination of two Bacillus strains suppresses Meloidogyne incognita and fungal pathogens, but does not enhance plant growth.

BACKGROUND: The combination of biocontrol agents is a desirable strategy to improve control efficacy against the root-knot nematode (RKN) Meloidogyne incognita under field conditions. However, strains compatibility is generally tested in vitro and incompatible combinations are normally not further examined in experiments in planta. Therefore, there is virtually no information on the performance of incompatible strains. In this study, we evaluated two Bacillus strains previously described as incompatible in vitro for effects on plant growth and suppression of M. incognita, pathogenic fungi and nematophagous fungi. RESULTS: Strains BMH and INV were shown to be closely related to Bacillus velezensis. These strains, when applied individually, reduced the number of galls and eggs of M. incognita by more than 90% in tomato roots. When BMH and INV were combined (BMH + INV), RKN suppression and tomato shoot weight were lower compared to single-strain applications. Additionally, metabolites in cell-free supernatants and volatile organic compounds (VOCs) from strains BMH and INV had strong effects against the plant pathogens M. incognita, Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsiii, but not against three species of nematophagous fungi. Although strain INV and the combination BMH + INV emitted fewer VOCs than strain BMH, they were still capable of killing second-stage juveniles of M. incognita. CONCLUSIONS: Bacillus strains BMH and INV inhibited M. incognita and fungal pathogens, and promoted tomato growth. However, strain INV emitted fewer VOCs and the combination BMH + INV did not enhance the activity of the biocontrol strains against the RKN or their capacity to promote plant growth. © 2021 Society of Chemical Industry.

Slight induction and strong inhibition of Heterodera glycines hatching by short-chain molecules released by different plant species.

New management tools are necessary to reduce the damage caused by the soybean cyst nematode (SCN), Heterodera glycines. Identification of molecules that can stimulate second-stage juveniles (J2) hatching in an environment without food may contribute to that. In in vitro experiments, we evaluate the effect of volatile organic compounds (VOCs) released by soybean (Glycine max), bean (Phaseolus vulgaris), ryegrass (Lolium multiflorum), and alfalfa (Medicago sativa) on H. glycines egg hatching. VOCs released by all plant species significantly (p < 0.05) increased egg hatching. Short-chain molecules released by leaves and roots of soybean and bean increased the hatching up to 71.4%. The analysis of the volatilome done by gas chromatography coupled with mass spectrometry revealed 44 compounds in the plant emissions. Four of them, namely 3-octanol, 1-hexanol, hexanal and linalool were tested individually as hatching inductors. Under concentrations of 200, 600, and 1,000 µg/ml there was no hatching induction of H. glycines J2 by these compounds. On the other hand, in these concentrations, the compounds 3-octanol and 1-hexanol caused hatching reduction with values similar to the commercial nematicide carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methyl carbamate). In subsequent tests, the compounds 1-hexanol and 3-octanol showed lethal concentration values required to kill 50% of thenematode population (LC50) of 210 and 228 µg/ml, respectively, in the first experiment and, 230 and 124 µg/mlin the second one. Although we have not identified any molecules acting as hatching factor (HF), here we present a list (44 candidate molecules) that can be explored in future studies to find an efficient HF.

O-bearing complex organic molecules at the cyanopolyyne peak of TMC-1: detection of C2H3CHO, C2H3OH, HCOOCH3, and CH3OCH3.

We report the detection of the oxygen-bearing complex organic molecules propenal (C2H3CHO), vinyl alcohol (C2H3OH), methyl formate (HCOOCH3), and dimethyl ether (CH3OCH3) toward the cyanopolyyne peak of the starless core TMC-1. These molecules are detected through several emission lines in a deep Q-band line survey of TMC-1 carried out with the Yebes 40m telescope. These observations reveal that the cyanopolyyne peak of TMC-1, which is the prototype of cold dark cloud rich in carbon chains, contains also O-bearing complex organic molecules like HCOOCH3 and CH3OCH3, which have been previously seen in a handful of cold interstellar clouds. In addition, this is the first secure detection of C2H3OH in space and the first time that C2H3CHO and C2H3OH are detected in a cold environment, adding new pieces in the puzzle of complex organic molecules in cold sources. We derive column densities of (2.2 ± 0.3) × 1011 cm™2, (2.5 ± 0.5) × 1012 cm-2, (1.1 ± 0.2) × 1012 cm-2, and (2.5 ± 0.7) × 1012 cm-2 for C2H3CHO, C2H3OH, HCOOCH3, and CH3OCH3, respectively. Interestingly, C2H3OH has an abundance similar to that of its well known isomer acetaldehyde (CH3CHO), with C2H3OH/CH3CHO ~ 1 at the cyanopolyyne peak. We discuss potential formation routes to these molecules and recognize that further experimental, theoretical, and astronomical studies are needed to elucidate the true mechanism of formation of these O-bearing complex organic molecules in cold interstellar sources.

The sulphur saga in TMC-1: Discovery of HCSCN and HCSCCH.

We report the detection, for the first time in space, of cyano thioformaldehyde (HCSCN) and propynethial (HCSCCH) towards the starless core TMC-1. Cyano thioformaldehyde presents a series of prominent a- and b-type lines, which are the strongest previously unassigned features in our Q-band line survey of TMC-1. Remarkably, HCSCN is four times more abundant than cyano formaldehyde (HCOCN). On the other hand, HCSCCH is five times less abundant than propynal (HCOCCH). Surprisingly, we find an abundance ratio HCSCCH/HCSCN of ∼ 0.25, in contrast with most other ethynyl-cyanide pairs of molecules for which the CCH-bearing species is more abundant than the CN-bearing one. We discuss the formation of these molecules in terms of neutral-neutral reactions of S atoms with CH2CCH and CH2CN radicals as well as of CCH and CN radicals with H2CS. The calculated abundances for the sulphur-bearing species are, however, significantly below the observed values, which points to an underestimation of the abundance of atomic sulphur in the model or to missing formation reactions, such as ion-neutral reactions.

Cumulene carbenes in TMC-1: Astronomical discovery of l-H2C5 ☠.

We report the first detection in space of the cumulene carbon chain l-H2C5. A total of eleven rotational transitions, with Jup = 7-10 and Ka = 0 and 1, were detected in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. We derive a column density of (1.8±0.5)×1010 cm-2. In addition, we report observations of other cumulene carbenes detected previously in TMC-1, to compare their abundances with the newly detected cumulene carbene chain. We find that l-H2C5 is ~4.0 times less abundant than the larger cumulene carbene l-H2C6, while it is ~300 and ~500 times less abundant than the shorter chains l-H2C3 and l-H2C4. We discuss the most likely gas-phase chemical routes to these cumulenes in TMC-1 and stress that chemical kinetics studies able to distinguish between different isomers are needed to shed light on the chemistry of C n H2 isomers with n > 3.

Pure hydrocarbon cycles in TMC-1: Discovery of ethynyl cyclopropenylidene, cyclopentadiene and indene.

We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c-C3HCCH (ethynyl cyclopropenylidene), c-C5H6 (cyclopentadiene) and c-C9H8 (indene). We derive a column density of 3.1 × 1011 cm-2 for the former cycle and similar values, in the range (1-2) × 1013 cm-2, for the two latter molecules. This means that cyclopentadiene and indene, in spite of their large size, are exceptionally abundant, only a factor of five less abundant than the ubiquitous cyclic hydrocarbon c-C3H2. The high abundance found for these two hydrocarbon cycles, together with the high abundance previously found for the propargyl radical (CH2CCH) and other hydrocarbons like vinyl and allenyl acetylene (Agúndez et al. 2021; Cernicharo et al. 2021a,b), start to allow us to quantify the abundant content of hydrocarbon rings in cold dark clouds and to identify the intermediate species that are probably behind the in situ bottom-up synthesis of aromatic cycles in these environments. While c-C3HCCH is most likely formed through the reaction between the radical CCH and c-C3H2, the high observed abundances of cyclopentadiene and indene are difficult to explain through currently proposed chemical mechanisms. Further studies are needed to identify how are five- and six-membered rings formed under the cold conditions of clouds like TMC-1.

Detection of deuterated methylcyanoacetylene, CH2DC3N, in TMC-1.

We report the first detection in space of the single deuterated isotopologue of methylcyanoacetylene, CH2DC3N. A total of fifteen rotational transitions, with J = 8-12 and Ka = 0 and 1, were identified for this species in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. The observed frequencies were used to derive for the first time the spectroscopic parameters of this deuterated isotopologue. We derive a column density of (8.0 ± 0.4) × 1010 cm-2. The abundance ratio between CH3C3N and CH2DC3N is ∼22. We also theoretically computed the principal spectroscopic constants of 13C isotopologues of CH3C3N and CH3C4H and those of the deuterated isotopologues of CH3C4H for which we could expect a similar degree of deuteration enhancement. However, we have not detected either CH2DC4H nor CH3C4D nor any 13C isotopologue. The different observed deuterium ratios in TMC-1 are reasonably accounted for by a gas phase chemical model where the low temperature conditions favor deuteron transfer through reactions with H2D+.