A four-years retrospective study: Clinical outcomes of XEN45 in patients with glaucoma.

INTRODUCTION: To evaluate the long-term effectiveness and safety of XEN45 implant, either alone or in combination with cataract surgery, in patients with glaucoma. METHODS: Retrospective and single center study conducted on consecutive patients who underwent a XEN45 implant, either alone or in combination with cataract surgery, between November 2016 and October 2021. The primary endpoint was the mean IOP lowering from preoperative values. RESULTS: Among the 230 screened patients, 206 eyes (176 patients) were included. Fifty-three (25.7%) eyes had undergone XEN-alone and 153 (74.3%) eyes had undergone a combined procedure (XEN+Phacoemulsification). The mean preoperative intraocular pressure (IOP) was significantly higher in the XEN-alone (22.2±5.9 mmHg) than in the XEN+Phaco (19.8±4.5 mmHg) group (p=0.0035). In the overall study population, the mean preoperative IOP was significantly lowered from 20.5±5.0 mmHg to 15.8±4.4 at year-4, p<0.0001. The mean preoperative (95% CI) IOP was significantly lowered from 22.2 (20.6 to 23.8) mmHg and 19.8 (19.1 to 20.6) mmHg to 15.6 (12.2 to 16.9) mmHg and 15.9 (15.2 to 16.5) mmHg at year-4 in the XEN-alone and XEN+Phaco groups, respectively (p<0.0001 each, respectively). The number of ocular hypotensive medications was significant reduced from 2.6±1.0 drugs to 1.3±1.3 drugs, with no significant differences between XEN-alone and XEN+Phaco groups (p=0.1671). On the first postoperative day, 62 (30.1%) eyes presented some type of complication. Fifteen (7.3%) eyes underwent a needling procedure. CONCLUSION: XEN45, either alone or in combination with phacoemulsification, significantly lowered the IOP and reduce the need of ocular hypotensive medication in the long-term.

Volatile Profiles and DNA Barcodes of Myrtaceae Species with Occurrence in the Brazilian Amazon.

Myrtaceae family includes many species with taxonomic challenges, making it one of the most complex families to identify. This study used DNA barcoding to find molecular markers for species authentication based on the Myrtaceae family's chemical composition and genetic diversity. Essential oils and genetic material were extracted from the leaves of six different species: Eugenia uniflora, E. patrisii, Myrcia splendens, Psidium guajava, P. guineense, and Psidium sp. The samples were analyzed based on compound classes and grouped into two categories. Group I included samples with high amounts of oxygenated sesquiterpenes (3.69-76.05 %) and fatty acid derivatives (0.04-43.59 %), such as E. uniflora, Myrcia splendens, and E. patrisii. Group II included samples P. guajava, P. guineense, and Psidium sp., which had a significant content of monoterpene hydrocarbons (0.69-72.35 %), oxygenated sesquiterpenes (8.06-68.1 %), phenylpropanoids (0.45-22.59 %), and sesquiterpene hydrocarbons (0.27-21.84 %). The PsbA-trnH gene sequences had a high genetic variability, allowing the species to be distinguished. A phylogenetic analysis showed two main clusters with high Bootstrap values corresponding to the subtribes Eugeniineae, Myrciinae, and Pimentinae. The results suggest a weak correlation between genetic and chemical data in these Myrtaceae species.

Smartphone-Based Methodology Applied to Electromagnetic Field Exposure Assessment.

This study presents the measurements of exposure to electromagnetic fields, carried out comparatively following standard methods from fixed sites using a broadband meter and using a smartphone on which an App designed for this purpose has been installed. The results of two measurement campaigns carried out on the campus of the University of Alcalá over an area of 1.9 km2 are presented. To characterize the exposure, 20 fixed points were measured in the first case and 860 points along the route made with a bicycle in the last case. The results obtained indicate that there is proportionality between the two methods, making it possible to use the smartphone for comparative measurements. The presented methodology makes it possible to characterize the exposure in the area under study in four times less time than that required with the traditional methodology.

Antinociceptive and anti-inflammatory activities of Ayapana triplinervis essential oil rich in thymohydroquinone dimethyl ether from Brazil.

Ayapana triplinervis (M.Vahl) R.M.King & H.Rob. (Asteraceae), popularly known as japana, is a tropical, aromatic subshrub widely used as tea to combat some diseases. The essential oil was obtained from the leaves by hydrodistillation (3 h), and the chemical composition was analyzed by gas chromatography coupled to mass spectrometry. For in vivo assays, Mus musculus/Swiss mice were used to evaluate oral acute toxicological (at dose of 2000 mg/kg); peripheral and central analgesic for abdominal contortion (doses of 6.25, 12.5, 25, 50 and 100 mg/kg), hot plate test (12.5, 25, 50, and 100 mg/kg) and formalin (25, 50 and 100 mg/kg); open field test (100 mg/kg); and anti-inflammatory by ear swelling induced by xylene (6.25,12.5, 25, 50, and 100 mg/kg). The yield of A. triplinervis essential oil (AtEO) was 4.6%, and the oxygenated monoterpene 2,5-dimethoxy-p-cymene was the major compound in this study (63.6%). AtEO at a dose of 2,000 mg/kg orally did not change the behavior patterns or mortality of the animals; liver and kidney biochemical levels were similar to the control group, indicating no liver and kidney toxicity. Moreover, AtEO, at doses of 6.25, 12.5, 25, 50, and 100 mg/kg, reduced abdominal contortions by 21%, 54%, 91%, 58%, and 55%, respectively. In the hot plate test, AtEO showed a significant increase in latency time in the 60-min interval at doses of 25 mg/kg (11.3 ± 3.3 s) and 100 mg/kg (11.9 ± 0.9 s). In the first phase of the formalin test, AtEO decreased paw licking time at doses of 25, 50, and 100 mg/kg, with inhibition of 22%, 38%, and 83%; in the second phase, the same doses, decreased licking time with inhibition of 24%, 34%, and 76%. AtEO did not present a significant change in the spontaneous locomotor activity of the animals. Doses of 6.25, 12.5, 25, 50, and 100 mg/kg significantly reduced ear edema induced by topical application of xylene with percentages of 40%, 39%, 54%, 45%, and 45%, respectively. So, AtEO demonstrated low acute oral toxicity and exhibited significant antinociceptive and anti-inflammatory actions, consistent with the use of A. triplinervis in traditional medicine.

Structure-Based Optimization of Carbendazim-Derived Tubulin Polymerization Inhibitors through Alchemical Free Energy Calculations.

Carbendazim derivatives, commonly used as antiparasitic drugs, have shown potential as anticancer agents due to their ability to induce cell cycle arrest and apoptosis in human cancer cells by inhibiting tubulin polymerization. Crystallographic structures of α/ß-tubulin multimers complexed with nocodazole and mebendazole, two carbendazim derivatives with potent anticancer activity, highlighted the possibility of designing compounds that occupy both benzimidazole- and colchicine-binding sites. In addition, previous studies have demonstrated that the incorporation of a phenoxy group at position 5/6 of carbendazim increases the antiproliferative activity in cancer cell lines. Despite the significant progress made in identifying new tubulin-targeting anticancer compounds, further modifications are needed to enhance their potency and safety. In this study, we explored the impact of modifying the phenoxy substitution pattern on antiproliferative activity. Alchemical free energy calculations were used to predict the binding free energy difference upon ligand modification and define the most viable path for structure optimization. Based on these calculations, seven compounds were synthesized and evaluated against lung and colon cancer cell lines. Our results showed that compound 5a, which incorporates an α-naphthyloxy substitution, exhibits the highest antiproliferative activity against both cancer lines (SK-LU-1 and SW620, IC50 < 100 nM) and induces morphological changes in the cells associated with mitotic arrest and mitotic catastrophe. Nevertheless, the tubulin polymerization assay showed that 5a has a lower inhibitory potency than nocodazole. Molecular dynamics simulations suggested that this low antitubulin activity could be associated with the loss of the key H-bond interaction with V236. This study provides insights into the design of novel carbendazim derivatives with anticancer activity.

Brentuximab vedotin in the treatment of cutaneous T-cell lymphomas: Data from the Spanish Primary Cutaneous Lymphoma Registry.

BACKGROUND: Brentuximab vedotin (BV) has been approved for CD30-expressing cutaneous T-cell lymphoma (CTCL) after at least one previous systemic treatment. However, real clinical practice is still limited. OBJECTIVES: To evaluate the response and tolerance of BV in a cohort of patients with CTCL. METHODS: We analysed CTCL patients treated with BV from the Spanish Primary Cutaneous Lymphoma Registry (RELCP). RESULTS: Sixty-seven patients were included. There were 26 females and the mean age at diagnosis was 59 years. Forty-eight were mycosis fungoides (MF), 7 Sézary syndrome (SS) and 12 CD30+ lymphoproliferative disorders (CD30 LPD). Mean follow-up was 18 months. Thirty patients (45%) showed at least 10% of CD30+ cells among the total lymphocytic infiltrate. The median number of BV infusions received was 7. The overall response rate (ORR) was 67% (63% in MF, 71% in SS and 84% in CD30 LPD). Ten of 14 patients with folliculotropic MF (FMF) achieved complete or partial response (ORR 71%). The median time to response was 2.8 months. During follow-up, 36 cases (54%) experienced cutaneous relapse or progression. The median progression free survival (PFS) was 10.3 months. The most frequent adverse event was peripheral neuropathy (PN) (57%), in most patients (85%), grades 1 or 2. CONCLUSIONS: These results confirm the efficacy and safety of BV in patients with advanced-stage MF, and CD30 LPD. In addition, patients with FMF and SS also showed a favourable response. Our data suggest that BV retreatment is effective in a proportion of cases.

Chemical Composition of Essential Oil from Mosses from the Brazilian Atlantic Forest.

This study aimed to report the unprecedented volatile composition of the mosses Phyllogonium viride BRID, Orthotichella rigida (MÜLL.HAL.) B. H. ALLEN & MAGILL and Schlotheimia rugifolia (HOOK.) SCHWÄGR occurring in the Brazilian Atlantic Forest, in order to elucidate the chemical composition of these species and enrich the chemotaxonomic knowledge of mosses. 28 compounds were identified, the major constituent being hexadecanoic acid, also known as palmitic acid, specifically P. viride com (38.55 %), O. rigida com (17.17 %) and S. rugifolia com (24.94 %), followed by phytol, P. viride com (3.92 %), O. rigida com (28.57 %) and S. rugifolia com (36.13 %). In addition, there was a prevalence of aliphatic hydrocarbons (25 %) and fatty acids (17.8 %) in the evaluated samples. These data contribute to the generation of new scientific information about the chemical constitution of mosses, still little studied, enriching the chemotaxonomic collection of the taxon.

Seasonal and Circadian Evaluation of the Essential Oil of Dizygostemon riparius (Plantaginaceae), a Wild Flavoring Herb from East Maranhão, Brazil.

Dizygostemon riparius (Plantaginaceae) is an aromatic herbal species known as "Melosa", endemic to the Municipality of São Benedito do Rio Preto, East Maranhão state, Brazil. It has a refreshing and pleasant aroma and is used for food flavoring and controlling domestic animal parasites. This work aimed to evaluate the seasonal and circadian influence on the composition and production of essential oils (EOs) from D. riparius. The plant aerial parts were hydrodistilled, and the oils were analyzed by GC and GC/MS. The seasonal study was conducted from August 2019 to July 2020, and the circadian study in dry (November) and rainy (May) periods, at 6 am, 12 am, and 6 pm. The results showed that the medium EOs yield was 2.8 %, and the primary constituents (>2 %) were endo-fenchyl acetate (30.5-42.1 %) and endo-fenchol (31.6-37.4 %), (E)-caryophyllene (2.8-7.6 %), α-fenchene (3.3-6.5 %), p-cymene (0.7-4.5 %), and caryophyllene oxide (1.4-2.7 %). Yield and composition of EOs did not significantly correlate with the climatic parameters, but their seasonal percentages influenced their two main components due to precipitation and solar radiation environmental factors. Quantitative variability in the EOs composition during the dry and rainy seasons was observed in the circadian period. These data may be significant for the plant's economic use.

Siparuna guianensis Essential Oil Antitumoral Activity on Ehrlich Model and Its Effect on Oxidative Stress.

This work aims to evaluate the chemical composition, in vitro antioxidant capacity, and in vivo antitumoral activity of S. guianensis essential oil against Ehrlich's ascitic carcinoma and the effects on oxidative stress. The animals (Mus musculus) received a daily dose of S. guianensis oil orally (100 mg/kg) for 9 days. The main constituents of essential oil were curzerenone (16.4±1.5 %), drimenol (13.7±0.2 %), and spathulenol (12.4±0.8 %). S. guianensis oil showed antioxidant activity, inhibiting 11.1 % of DPPH radicals (95.7 mgTE/g); and 15.5 % of the ß-carotene peroxidation. The group treated with S. guianensis showed a significant reduction in tumor cells (59.76±12.33) compared to the tumor group (96.88±19.15). Essential oil of S. guianensis decreased MDA levels and increased SOD levels in liver tissue. The essential oil of S. guianensis reduced oxidative stress, and showed antitumor and antioxidant activity, being characterized as a new chemical profile in the investigation of pathologies such as cancer.

Chronic Glaucoma Induced in Rats by a Single Injection of Fibronectin-Loaded PLGA Microspheres: IOP-Dependent and IOP-Independent Neurodegeneration.

To evaluate a new animal model of chronic glaucoma induced using a single injection of fibronectin-loaded biodegradable PLGA microspheres (Ms) to test prolonged therapies. 30 rats received a single injection of fibronectin-PLGA-Ms suspension (MsF) in the right eye, 10 received non-loaded PLGA-Ms suspension (Control), and 17 were non-injected (Healthy). Follow-up was performed (24 weeks), evaluating intraocular pressure (IOP), optical coherence tomography (OCT), histology and electroretinography. The right eyes underwent a progressive increase in IOP, but only induced cohorts reached hypertensive values. The three cohorts presented a progressive decrease in ganglion cell layer (GCL) thickness, corroborating physiological age-related loss of ganglion cells. Injected cohorts (MsF > Control) presented greater final GCL thickness. Histological exams explain this paradox: the MsF cohort showed lower ganglion cell counts but higher astrogliosis and immune response. A sequential trend of functional damage was recorded using scotopic electroretinography (MsF > Control > Healthy). It seems to be a function-structure correlation: in significant astrogliosis, early functional damage can be detected by electroretinography, and structural damage can be detected by histological exams but not by OCT. Males presented higher IOP and retinal and GCL thicknesses and lower electroretinography. A minimally invasive chronic glaucoma model was induced by a single injection of biodegradable Ms.

Antidepressant Effects of Essential Oils: A Review of the Past Decade (2012-2022) and Molecular Docking Study of Their Major Chemical Components.

Depression is a mental disorder that affects more than 300 million people worldwide. The medications available for treatment take a long time to exhibit therapeutic results and present several side effects. Furthermore, there is a decrease in the quality of life of people suffering from this affliction. Essential oils are traditionally used to relieve the symptoms of depression due to the properties of the constituents of these oils to cross the blood-brain barrier acting on depression-related biological receptors associated with reduced toxicity and side effects. In addition, compared to traditional drugs, they have several administration forms. This review provides a comprehensive assessment of studies on plants whose essential oil has exhibit antidepressant activity in the past decade and the mechanism of action of the major components and models tested. An additional in silico study was conducted with the frequent compounds in the composition of these essential oils, providing a molecular approach to the mechanism of action that has been reported in the past decade. This review is valuable for the development of potential antidepressant medications in addition to providing a molecular approach to the antidepressant mechanism of action of the major volatile compounds that have been reported in the past decade.

Enhancing Giardicidal Activity and Aqueous Solubility through the Development of "RetroABZ", a Regioisomer of Albendazole: In Vitro, In Vivo, and In Silico Studies.

Parasitic diseases, including giardiasis caused by Giardia lamblia (G. lamblia), present a considerable global health burden. The limited effectiveness and adverse effects of current treatment options underscore the necessity for novel therapeutic compounds. In this study, we employed a rational design strategy to synthesize retroalbendazole (RetroABZ), aiming to address the limitations associated with albendazole, a commonly used drug for giardiasis treatment. RetroABZ exhibited enhanced in vitro activity against G. lamblia trophozoites, demonstrating nanomolar potency (IC50 = 83 nM), outperforming albendazole (189 nM). Moreover, our in vivo murine model of giardiasis displayed a strong correlation, supporting the efficacy of RetroABZ, which exhibited an eleven-fold increase in potency compared to albendazole, with median effective dose (ED50) values of 5 µg/kg and 55 µg/kg, respectively. A notable finding was RetroABZ's significantly improved water solubility (245.74 µg/mL), representing a 23-fold increase compared to albendazole, thereby offering potential opportunities for developing derivatives that effectively target invasive parasites. The molecular docking study revealed that RetroABZ displays an interaction profile with tubulin similar to albendazole, forming hydrogen bonds with Glu198 and Cys236 of the ß-tubulin. Additionally, molecular dynamics studies demonstrated that RetroABZ has a greater number of hydrophobic interactions with the binding site in the ß-tubulin, due to the orientation of the propylthio substituent. Consequently, RetroABZ exhibited a higher affinity compared to albendazole. Overall, our findings underscore RetroABZ's potential as a promising therapeutic candidate not only for giardiasis but also for other parasitic diseases.

Chemometrics of the Composition and Antioxidant Capacity of Hyptis crenata Essential Oils from Brazil.

Hyptis crenata (Pohl) ex Benth is used in traditional medicine as an analgesic to treat general pain. Six Hyptis crenata samples (Hc-1 to Hc-6) were collected in Pará state, Brazil. The leaf essential oils were obtained by hydrodistillation, and GC-MS and GC-FID were used to analyze their chemical compositions. The antioxidant capacity was measured in vitro using DPPH and carotene/linoleic acid assays. Chemometrics analysis (PCA, HCA, and clustered heat map) were used to identify the sample relationships between those collected in this study and those from the literature (Hc-7 to Hc-16) samples. According to the main chemical constituents identified in the samples described in this work and the literature, the sixteen samples were classified into ten groups. Group I was characterized by 1,8-cineole (31.0%), α-pinene (13.6%), (E)-caryophyllene (7.8%), and ß-pinene (7.6%); and Group IV was characterized by 1,8-cineole (17.4-23.5%), α-pinene (15.7-23.5%), ß-pinene (10.5-13.4%), and limonene (8.5-9.7%). Both groups are described for the first time. The total antioxidant capacity was expressed in Trolox Equivalent Antioxidant Capacity values (TEAC): TEAC of Hc-5 (551.9 mg.TE/g) and Hc-6 (475.1 mg.TE/g). In the ß-carotene/linoleic acid assay, the highest inhibition was from Hc-2 (40.0%), Hc-6 (39.0%), and Hc-3 (29.4%).

Seasonal Variation in Essential Oil Composition and Antioxidant Capacity of Aniba canelilla (Lauraceae): A Reliable Source of 1-Nitro-2-phenylethane.

Aniba canelilla (Kunth) Mez essential oil has many biological activities due to its main compound 1-nitro-2-phenylethane (1N2F), followed by methyleugenol, a carcinogenic agent. This study analyzed the influence of seasonality on yields, antioxidant capacity, and 1N2F content of A. canelilla leaf and twig essential oils. Essential oils (EOs) were extracted with hydrodistillation and analyzed with gas chromatography coupled to mass spectrometry and a flame ionization detector. Antioxidant capacity was measured using the free radical scavenging method (DPPH). Chemometric analyses were carried out to verify the influence of climatic factors on the production and composition of EOs. 1-Nitro-2-phenylethane was the major constituent in A. canelilla EOs throughout the seasonal period (68.0-89.9%); methyleugenol was not detected. Essential oil yields and the 1N2F average did not show a statistically significant difference between the dry and rainy seasons in leaves and twigs. Moderate and significant correlations between major compounds and climate factor were observed. The twig oils (36.0 ± 5.9%) a showed greater antioxidant capacity than the leaf oils (20.4 ± 5.0%). The PCA and HCA analyses showed no statistical differences between the oil samples from the dry and rainy seasons. The absence of methyleugenolin in all months of study, described for the first time, makes this specimen a reliable source of 1N2F.

Director Distortion and Phase Modulation in Deformable Nematic and Smectic Liquid Crystal Spheroids.

The growing interest in integrating liquid crystals (LCs) into flexible and miniaturized technologies brings about the need to understand the interplay between spatially curved geometry, surface anchoring, and the order associated with these materials. Here, we integrate experimental methods and computational simulations to explore the competition between surface-induced orientation and the effects of deformable curved boundaries in uniaxially and biaxially stretched nematic and smectic microdroplets. We find that the director field of the nematic LCs upon uniaxial strain reorients and forms a larger twisted defect ring to adjust to the new deformed geometry of the stretched droplet. Upon biaxial extension, the director field initially twists in the now oblate geometry and subsequently transitions into a uniform vertical orientation at high strains. In smectic microdroplets, on the other hand, LC alignment transforms from a radial smectic layering to a quasi-flat layering in a compromise between interfacial and dilatation forces. Upon removing the mechanical strain, the smectic LC recovers its initial radial configuration; however, the oblate geometry traps the nematic LC in the metastable vertical state. These findings offer a basis for the rational design of LC-based flexible devices, including wearable sensors, flexible displays, and smart windows.

Post hoc Analysis of a Randomized, Controlled, Phase 2 Study to Assess Response Rates with Chlormethine/Mechlorethamine Gel in Patients with Stage IA-IIA Mycosis Fungoides.

BACKGROUND: Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma. Patients can be treated using chlormethine gel, a skin-directed therapy developed and approved for MF. In the randomized, controlled 201 trial, chlormethine gel was found to be noninferior to equal-strength chlormethine ointment. However, there remains a need to gain more insight into outcome measures after treatment. OBJECTIVE: The aim of this study was to further investigate the potential of chlormethine gel treatment through a novel post hoc analysis of the 201 trial data (NCT00168064). METHODS: Patients were randomized to chlormethine gel or ointment; response assessments included Composite Assessment of Index Lesion Severity (CAILS) and total body surface area (BSA). In this post hoc analysis, additional subgroup response analyses were performed for stage IA/IB-IIA MF. Very good partial response (75 to <100% improvement) was included as an additional response category. Time to response and overall response trends were determined. Finally, multivariate time-to-event analyses were performed to determine whether associations were observed between treatment frequency, response, and adverse events. RESULTS: Response rates were significantly higher for patients with stage IA MF for CAILS (intent-to-treat [p = 0.0014] and efficacy-evaluable [EE; p = 0.0036] populations) and BSA (EE population [p = 0.0488]) treated with gel versus ointment. Time to first CAILS response and response trends were better for all-stage gel-treated patients overall. No association was seen between treatment frequency and response or occurrence of adverse events at the following visit. An association was observed between the occurrence of contact dermatitis and improved clinical response at the next visit (p = 0.0001). CONCLUSION: This post hoc analysis shows that treatment with chlormethine gel may result in higher and faster response rates compared with chlormethine ointment, which confirms and expands results reported in the original analysis. The incidence of contact dermatitis may potentially be a prognostic indicator for clinical response; this needs to be confirmed in a larger population.

The Volatile Profiles and DNA Barcodes of Lauraceae Species from the Ocotea Complex with Occurrence in the Brazilian Amazon.

The Ocotea complex accommodates most of the taxonomic diversity of Neotropical Lauraceae with economic importance and biological potential attributed to their essential oils (EOs) and extracts. However, the botanical taxonomy has had limitations due to the difficulty of identifying and delimiting species and genera. The chemical and molecular markers of Ocotea complex species in Pará state, Brazil, were assessed according to their EO compositions and DNA sequences of matK, trnL-trnF, and ITS regions. The multivariate analysis of EOs constituents has classified them into two main clusters characterized by oils rich in (I) terpenoids and phenylpropanoids and (II) sesquiterpenes. We conducted a phylogenetic analysis of species based on DNA barcode sequences on the Bayesian Inference (PP: 0.70-1,0) and Maximum Likelihood (BS: 72-100 %). The comparison between the volatile profiles and phylogenetic data indicates two main groups for these species collected from the Ocotea complex.

New Cable Delay Measurement System for VGOS Stations.

This paper presents the new cable delay measurement system (CDMS) designed at Yebes Observatory (IGN, Spain), which is required for the VLBI Global Observing System (VGOS) stations. This system measures the phase difference between the 5 MHz reference signal from the hydrogen maser and the 5 MHz signal that reaches the broadband receiver through a coaxial cable, for the generation of calibration tones. As a result, the system detects the changes in the length of that coaxial cable due to temperature variations along the cable run and flexures caused by VGOS radio telescope movements. This CDMS outperforms the previous versions: firstly, it does not require a frequency counter for phase/delay measurements; secondly, it largely reduces the use of digital circuits; hence, reducing digital noise; and thirdly, it has a remotely controlled automatic calibration subsystem. The system was tested in the laboratory and in the radio telescope, and the measurements of both set-ups are shown. These measurements include the total noise, accuracy, hysteresis, and stability. The results in the radio telescope can be correlated with the different factors that affect the cable, such as temperature and flexures. The system allows to achieve an RMS noise of less than 0.5 ps, significantly improving the requirements established in VGOS. The system is currently installed in the Red Atlántica de Estaciones Geodinámicas y Espaciales (RAEGE)Yebes VGOS 13.2 m radio telescope, and will be installed in the Norwegian Mapping Authority (NMA) twin VGOS radio telescopes, in the Finnish Geospatial Research Institute (FGI) VGOS station and in the RAEGE Santa María VGOS radio telescope (Açores, Portugal).

Variability in the Chemical Composition of Myrcia sylvatica (G. Mey) DC. Essential Oils Growing in the Brazilian Amazon.

Myrcia sylvatica (G. Mey) DC. is known as "insulin plant" because local communities use the infusions of various organs empirically to treat diabetes. The leaves of seven specimens of Myrcia sylvatica (Msy-01 to Msy-07) were collected in the Brazilian Amazon. Furthermore, the essential oils were extracted by hydrodistillation and analyzed by gas chromatography coupled to mass spectrometry, and their chemical compositions were submitted to multivariate analysis (Principal Component Analysis and Hierarchical Cluster Analysis). The multivariate analysis displayed the formation of four chemical profiles (chemotypes), described for the first time as follows: chemotype I (specimen Msy-01) was characterized by germacrene B (24.5%), γ-elemene (12.5%), and ß-caryophyllene (10.0%); chemotype II (specimens Msy-03, -06 and -07) by spathulenol (11.1-16.0%), germacrene B (7.8-20.7%), and γ-elemene (2.9-7.6%); chemotype III (Msy-04 and -05) by spathulenol (9.8-10.1%), ß-caryophyllene (2.5-10.1%), and δ-cadinene (4.8-5.6%); and chemotype IV, (Msy-02) by spathulenol (13.4%), caryophyllene oxide (15.0%), and α-cadinol (8.9%). There is a chemical variability in the essential oils of Myrcia sylvatica occurring in the Amazon region.

Chemical Composition and Variability of the Volatile Components of Myrciaria Species Growing in the Amazon Region.

Myrciaria (Myrtaceae) species have been well investigated due to their chemical and biological relevance. The present work aimed to carry out the chemotaxonomic study of essential oils of the species M. dubia, M. floribunda, and M. tenella, sampled in the Brazilian Amazon and compare them with the volatile compositions from other Myrciaria species reported to Brazil and Colombia. The leaves of six Myrciaria specimens were collected (PA, Brazil) during the dry season, and their chemical compositions were analyzed by gas chromatography-mass spectrometer (GC-MS) and gas chromatography-flame ionization detector (GC-FID). The main compounds identified in the essential oils were monoterpenes with pinane and menthane skeletons, followed by sesquiterpenes with caryophyllane and cadinane skeletons. Among the sampled Myrciaria specimens, five chemical profiles were reported for the first time: profile I (M. dubia, α-pinene, 54.0-67.2%); profile II (M. floribunda, terpinolene 23.1%, α-phellandrene 17.7%, and γ-terpinene 8.7%); profile III (M. floribunda, γ-cadinene 17.5%, and an unidentified oxygenated sesquiterpene 15.0%); profile IV (M. tenella, E-caryophyllene 43.2%, and α-humulene 5.3%); and profile V (M. tenella, E-caryophyllene 19.1%, and caryophyllene oxide 41.1%). The Myrciaria chemical profiles showed significant variability in extraction methods, collection sites, plant parts, and genetic aspects.