We consider measurements of exclusive rare semi-tauonic
b
-hadron decays, mediated by the
b
→
s
τ
+
τ
-
transition, at a future high-energy circular electron–positron collider (FCC-
ee
). We argue ...that the high boosts of
b
-hadrons originating from on-shell
Z
boson decays allow for a full reconstruction of the decay kinematics in hadronic
τ
decay modes (up to discrete ambiguities). This, together with the potentially large statistics of
Z
→
b
b
¯
, opens the door for the experimental determination of
τ
polarizations in these rare
b
-hadron decays. In the light of the current experimental situation on lepton flavor universality in rare semileptonic
B
decays, we discuss the complementary short-distance physics information carried by the
τ
polarizations and suggest suitable theoretically clean observables in the form of single- and double-
τ
polarization asymmetries.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sesamol is a phenolic derivative. Its antioxidant activity is low than that of Trolox and depends on benzodioxole moiety. Thus, a molecular modification strategy through alkylation, inspired by ...natural and synthetic antioxidants, was studied by molecular modeling at the DFT/B3LYP level of theory by comparing the 6-31+G(d,p) and 6-311++G(2d,2p) basis sets. All proposed derivatives were compared to classical related antioxidants such as Trolox,
-butylated hydroxytoluene (BHT) and
-butylated hydroxyanisole (BHA). According to our results, molecular orbitals, single electron or hydrogen-atom transfers, spin density distributions, and alkyl substitutions at the ortho positions related to phenol moiety were found to be more effective than any other positions. The trimethylated derivative was more potent than Trolox.
-Butylated derivatives were stronger than all other alkylated derivatives and may be new alternative forms of modified antioxidants from natural products with applications in the chemical, pharmaceutical, and food industries.
The genus Psidium, belonging to the family Myrtaceae, encompasses several plant species rich in essential oils. Several studies involving different research areas have shown promising results for ...essential oils, which has attracted interest from diverse sectors, including pharmaceutical, food, and cosmetic industries. Thus, the objective of this study was to evaluate the biological activity of the essential oil extracted from Psidium bahianum leaves (EOPb) collected in an Atlantic Forest remnant in the northern coast of the state of Bahia, Brazil. EOPb was extracted by steam distillation and analyzed through proton nuclear magnetic resonance (1H-NMR). The free radical scavenging activity was assessed using the DPPH methodology (analyzing the scavenging of the stable free radical 1,1-diphenyl-2-picrylhydrazyl). Antimicrobial disk diffusion assays were conducted; toxicity was determined through assays on sheep erythrocytes and Artemia salina. 1H-NMR evaluation showed the presence mainly of monoterpenes and sesquisterpenes. The percentage of antioxidant activity was 18.03±2.53 53 for 125 125 µg mL-1. Antimicrobial assays showed that the essential oil at a concentration of 10 mg mL-1 inhibited the growth of the microorganisms Staphylococcus aureus, Bacillus subtilis, B. cereus, Micrococcus luteus, Escherichia coli, Aspergillus niger, Candida albicans, and C. glabrata. The toxicity results indicated that concentrations of EOPb at 10, 100, 250, and 500 µg mL-1 were not toxic to sheep erythrocytes. The toxicity assay on A. salina showed that the lethal concentration for 50% of individuals (LC50) within 24 and 48 hours were 371.48 and 302 µg mL-1 of EOPb, respectively, which were considered moderately toxic, whereas the LC50 within 72 horas was 33.11 µg mL-1, considered highly toxic. These findings are promising, as the essential oil from P. bahianum leaves showed antimicrobial activity against both Gram-positive and Gram-negative bacteria and fungi. The data obtained for the essential oil toxicity in A. salina could be tested on different tumor cell lines.
Abstract Plants possess a renewable source of metabolites with enormous chemical structural diversity, which may have potential therapeutic relevance. Furthermore, this chemical diversity favors the ...possibility of finding new and different chemical constituents with antimicrobial, antioxidant and anti-tumor activities. This work analyzed preliminary phytochemical profiles and evaluated the antimicrobial, antioxidant and cytotoxic activities of hexane extracts of leaves of ten species of the family Melastomataceae. Phytochemical screening was performed using staining methods while total phenols and flavonoids were quantified by spectrophotometry. Antimicrobial activity was evaluated using the disk diffusion method. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazil (DPPH) method. Toxicity was recorded using the lethality test with Artemia salina Leach (1819). Cytotoxic activity of the extracts was assessed in vitro with acute monocytic leukemia cells (THP-1). Phytochemical analysis detected the presence of tannins, terpenes, steroids, polyphenols and flavonoids and the absence of alkaloids. Clidemia capitellata (Bonpl.) D. Don had the greatest amount of polyphenols (205.95 mg/g ± 4.14) while Clidemia hirta (L.) D. Don had the highest content of total flavonoids (143.99 mg/g ± 4.18). The hexane extracts did not show antimicrobial activity nor toxicity against Artemia salina. The extract of Tibouchina francavillana Cogn. was the most active in sequestering the DPPH radical. The extracts showed cytotoxicity in THP-1 cells with the appearance of apoptotic bodies and cell death. The extracts of Miconia amoena, Clidemia sericea and Clidemia capitellata are non-toxic against Artemia salina and induce the formation of apoptotic bodies and cell death of the THP-1 lineage.
Resumo Os vegetais apresentam uma fonte renovável de metabólitos com enorme diversidade química estrutural, os quais podem apresentar potencial relevante na terapêutica, aumentando as possibilidades de encontrar novos e diferentes constituintes químicos com atividades antimicrobiana, antioxidante e antitumoral. Este trabalho analisou o perfil fitoquímico preliminar e as atividades antimicrobiana, antioxidante, citotóxica dos extratos em hexano das folhas de dez espécies da família Melastomataceae. A triagem fitoquímica foi executada utilizando métodos de coloração e quantificação de fenóis e flavonoides totais por espectrofotometria. A atividade antimicrobiana foi realizada pelo método de difusão em disco. A atividade antioxidante foi determinada pelo método 2,2-difenil-1-picrilhidrazila (DPPH). A toxicidade foi registrada utilizando o ensaio de letalidade com Artemia salina Leach (1819). A atividade citotóxica dos extratos foi realizada in vitro com células leucêmicas monocítica aguda (THP-1). A análise fitoquímica detectou a presença de taninos, terpenos, esteroides, polifenóis, flavonoides e ausência de alcaloides. A maior quantificação de polifenóis foi da Clidemia capitellata (Bonpl.) D. Don (205,95 mg/g ± 4,14) e o extrato de Clidemia hirta (L.) D. Don apresentou maior teor de flavonoides totais (143,99 mg/g ± 4,18). Os extratos hexânicos não demostraram atividade antimicrobiana e nem toxicidade frente à Artemia salina. O extrato de Tibouchina francavillana Cogn. foi o mais ativo no sequestro do radical DPPH. Os extratos apresentaram citotoxicidade em células THP-1, com visualização de corpos apoptóticos e morte celular. Os extratos de Miconia amoena, Clidemia sericea e Clidemia capitellata são atóxicos contra Artemia salina e induzem a formação de corpos apoptóticos e morte celular da linhagem THP-1.
This study evaluates the antifungal activity and mechanism of action of a new chemotype of
Lavandula multifida
from Portugal. The essential oil was analyzed by gas chromatography (GC) and gas ...chromatography/mass spectrometry (GC/MS), and the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) of the oil and its major compounds were determined against several pathogenic fungi responsible for candidosis, meningitis, dermatophytosis, and aspergillosis. The influence of the oil on the dimorphic transition in
Candida albicans
was also studied, as well as propidium iodide (PI) and FUN-1 staining of
C. albicans
cells by flow cytometry. The essential oil was characterized by high contents of monoterpenes, with carvacrol and
cis
-
β
-ocimene being the main constituents. The oil was more effective against dermatophytes and
Cryptococcus neoformans
, with MIC and MLC values of 0.16 μL/mL and 0.32 μL/mL, respectively. The oil was further shown to completely inhibit filamentation in
C. albicans
at concentrations below the respective MIC (0.08 μL/mL), with
cis
-
β
-ocimene being the main compound responsible for this inhibition (0.02 μL/mL). The flow cytometry results suggest a mechanism of action ultimately leading to cytoplasmic membrane disruption and cell death.
L. multifida
essential oil may be useful in complementary therapy to treat disseminated candidosis, since the inhibition of filamentation alone appears to be sufficient to treat this type of infection.
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Transurethral resection of bladder tumor (TURBT) is crucial in the treatment of bladder tumors and when incorrectly performed can cause staging mistakes. To avoid these errors, a ...second resection is recommended in selected cases. The aim of this study is to evaluate the surgeon's ability to predict histologically complete primary resection of newly diagnosed bladder tumors avoiding the need for a second TURBT.
This is a prospective, observational study involving 47 consecutive patients with newly diagnosed bladder tumors who had previously undergone primary TURBT, and met EAU criteria for second-look TURBT. Second-look TURBT specimens were analyzed for routine histological assessment and compared with the surgeon's impression of the tumor at initial resection.
Of 91 patients submitted to primary TURBT, 47 met the criteria for second-look TURBT. Second-look specimens revealed residual disease in 20.9% of patients and 3 (6.4%) of patients showed upstaging disease. The sensitivity of a senior to detect disease on second-look TURBT in relation to muscle invasion was 75%, and the specificity was 85%.
Second-look TURBT is crucial in the treatment of bladder cancer and cannot be replaced by a surgeon's opinion, so international recommendations should be followed. Supervision of less experienced surgeons is a cornerstone.
La resección transuretral del tumor vesical (RTUv) constituye un paso fundamental en el tratamiento de los tumores vesicales, ya que su incorrecta realización puede dar lugar a un estadiaje erróneo en estos pacientes. Para evitar estos errores, es recomendable realizar una segunda resección (re-RTU) en casos seleccionados. El objetivo de este estudio es evaluar la habilidad del cirujano para predecir que la primera resección del tumor de vejiga inicial está macroscópicamente completa, evitando la necesidad de una segunda RTUv (re-RTUv).
Se trata de un estudio prospectivo observacional en el que participaron 47 pacientes consecutivos diagnosticados de tumor vesical inicial, sometidos previamente a una primera RTUv y que cumplían los criterios de la EAU para someterse a una re-RTU vesical. Se tomaron muestras de la re-RTUv para su análisis histológico habitual y los resultados se compararon con la valoración del cirujano sobre el tumor al realizar la resección inicial.
De los 91 pacientes sometidos a la primera RTUv, 47 cumplían los criterios para una re-RTUv. En el 20,9% de los pacientes, las piezas de re-RTUv reportaron tumor residual y 3 (6,4%) de los pacientes habían sido infraestadiados en la primera resección. La sensibilidad los cirujanos senior para detectar la presencia de enfermedad en la re-RTUv según la afectación de la capa muscular fue del 75%, y la especificidad fue del 85%.
La re-RTUv es crucial en el tratamiento del cáncer de vejiga y no puede sustituirse por la valoración del cirujano, por lo que deben seguirse las recomendaciones de las guías internacionales. La supervisión a los cirujanos menos experimentados es fundamental.
Abstract We consider measurements of exclusive rare semi-tauonic b-hadron decays, mediated by the $$b \rightarrow s \tau ^+ \tau ^-$$ b→sτ+τ- transition, at a future high-energy circular ...electron–positron collider (FCC-ee). We argue that the high boosts of b-hadrons originating from on-shell Z boson decays allow for a full reconstruction of the decay kinematics in hadronic $$\tau $$ τ decay modes (up to discrete ambiguities). This, together with the potentially large statistics of $$Z\rightarrow b\bar{b}$$ Z→bb¯ , opens the door for the experimental determination of $$\tau $$ τ polarizations in these rare b-hadron decays. In the light of the current experimental situation on lepton flavor universality in rare semileptonic B decays, we discuss the complementary short-distance physics information carried by the $$\tau $$ τ polarizations and suggest suitable theoretically clean observables in the form of single- and double-$$\tau $$ τ polarization asymmetries.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Gabapentin improves myelin basic protein expression in the injured sciatic nerve.•Gabapentin ameliorates neuropathic pain behaviors.•Gabapentin has a dual role in improving neuropathic pain and ...nerve myelination following sciatic nerve injury.
Gabapentin (GBP) is an anti-convulsive drug often used as analgesic to control neuropathic pain. This study aimed at evaluating oral GBP treatment (30, 60, 120mg/kg, 60min prior to chronic constriction of the sciatic nerve (CCSN) along 15-day treatment post-injury, 12h/12h) by monitoring spontaneous and induced-pain behaviors in Wistar rats on 5th and 15th days post-injury during early neuropathic events. CCSN animals receiving saline were used as controls. Another aim of this study was to evaluate GBP effects on myelin basic protein (MBP) on the 5th and 15th days post-injury and nerve morphology by transmission electron microscopy to address nerve regeneration. On the 5th and 15th days, GBP (60mg/kg) reduced neuropathic pain behaviors (scratching and biting) in the ipsilateral paw and alleviated mechanical allodynia in comparison with the neuropathic saline group. GBP significantly increased climbing and rearing behaviors in CCSN and CCSN-free animals suggesting increased motor activity rather than sedation. We found three-fold significant increase in MBP expression by western blots on the 15th day when compared to controls. In addition, GPB (60mg/kg) improved nerve axonal, fiber and myelin area 15 days post-surgery. In conclusion, GBP alleviated mechanical and thermal allodynia and spontaneous pain-related behaviors and improved later nerve morphology. Our findings suggest that GBP improve nerve remyelination after chronic constriction of the sciatic nerve.
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