Evolution of nanostructure and mechanical properties of silver nano-particle in the confined region between graphene sheets: An atomistic investigation

Solidification and organization of silver nano-particle in a confined region between graphene sheets, shows much importance for the various application in the field of biomedical, electrochemical, coating materials, catalyst, metal-matrix nanocomposite etc. To understand the processes involved, we have studied the atomistic behaviour of solidification, organizations and mechanical properties of silver nano-particle in the bulk and as well as in confined region by molecular dynamics simulations. In the bulk, silver nano-particle shows phase transition from liquid to crystalline phase at a temperature, T ≈ 1030 ± 25 K. However, in the confined region, silver nano-particle depicts the same phase transition at a relatively higher temperature. The tensile stress, initiation of cracks and subsequent detachment of silver during tensile deformation depends upon the temperature and interfacial interactions. The tuning of 12–6 Lennard Jones interaction potential energy parameter between graphene and silver (εAg-C) drastically influenced the phase transition of silver nano-particle in the confined region. At a high interaction potential energy (εAg-C), silver nano-particle shows good wettability over the graphene sheets and depicts the phase transition at a higher temperature compared to lower interaction potential energy

Mjerenje naboja čestice (1 ≤ Z ≤ 3) proizvedenih u sudarima 60 A GeV/c 16O u emulziji i traženje čestica s razlomljenim nabojem

Measurement of charges (1 ≤ Z ≤ 3) of the projectile fragments in ultra–relativistic heavy–ion collisions (16O–emulsion at 60A GeV/c) was carried out by the measurement of lacunarity (L) of the track structure in nuclear emulsion track detector. No fractionally charged projectile fragment has been found in the present investigation.Proučavani su ultrarelativistički sudari teških iona (60 GeV/c 16O) u nuklearnoj emulziji. Naboji čestica (1 ≤ Z ≤ 3) određeni su prema lacunarnosti (L) tragova čestica u emulziji. Nisu nađene čestice s razlomljenim nabojem

Mjerenje naboja čestice (1 ≤ Z ≤ 3) proizvedenih u sudarima 60 A GeV/c 16O u emulziji i traženje čestica s razlomljenim nabojem

Measurement of charges (1 ≤ Z ≤ 3) of the projectile fragments in ultra–relativistic heavy–ion collisions (16O–emulsion at 60A GeV/c) was carried out by the measurement of lacunarity (L) of the track structure in nuclear emulsion track detector. No fractionally charged projectile fragment has been found in the present investigation.Proučavani su ultrarelativistički sudari teških iona (60 GeV/c 16O) u nuklearnoj emulziji. Naboji čestica (1 ≤ Z ≤ 3) određeni su prema lacunarnosti (L) tragova čestica u emulziji. Nisu nađene čestice s razlomljenim nabojem

Elektroencefalografske, elektrokardigrafske i spirometrijske promjene u koza uzrokovane propofolom

The effects of Propofol-induced electroencephalographic, electrocardiographic and spirometric changes were studied at a lower dose rate (0.4 mg/kg body mass, intravenously) and at higher dose rate (0.5 mg/kg body mass, intravenously) in four apparently healthy goats 10 to 14 months old, weighing 9 to 12 kg. Electroencephalographic results showed that anesthesia was induced with a change of distorted β wave patterns to α waves within one minute. The α wave patterns continued for 5 to 6 minutes at the lower dose (0.4 mg/kg body mass) while they persisted for 12 to 13 minutes at the higher dose (0.5 mg/kg body mass). At the lower dose, recovery was predictable after 5 minutes on reversal of the EEG pattern from α to β waves, whereas at the higher dose α wave patterns continued for 15 minutes. The occurrence of the righting reflfl ex was noticed after the disappearance of α waves. The heart rate increased with both the dose rates within the fifi rst 5 minutes and decreased after 10 and 15 minutes of induction. Inverted T waves were found in two goats at the lower dose while at the higher dose it was found to be inverted in three of the four goats. One of the goats inducted with the higher dose showed tachycardia, with ectopic beats from the 5th to 7th minute post induction. On average, apnea was noticed for the fifi rst 30 seconds at the lower dose and for 42 seconds at the higher dose. One of the animals receiving the higher dose showed apnea for 314 seconds. This goat was given artififi cial respiration after 106 seconds and then again after 296 seconds to resuscitate it. The animal showed severe respiratory distress with abdominal respiration during the fifi rst few seconds. The tidal volume did not return to normal until 15 minutes after induction. This indicates that Propofol has a respiratory depressant activity in goats and positive pressure ventilation must be provided. It does not induce analgesia and should be accompanied by analgesics .Istraživane su elektroencefalografske, elektrokardiografske i spirometrijske promjene uzrokovane propofolom u četiri zdrave koze u dobi od 10 do 14 mjeseci, mase od 9 do 12 kg. Propofol im je bio primijenjen intravenski u malim (0,4 mg/kg tjelesne mase) i većim (0,5 mg/kg tjelesne mase) dozama. Rezultati elektroencefalografi je pokazali su da se pri izazvanoj anesteziji obrazac β vala promijenio u α valove u tijeku jedne minute. Obrasci α vala nastavili su se tijekom 5 do 6 minuta kod primjene male doze (0,4 mg/kg tjelesne mase) dok su kod primjene veće doze (0,5 mg/kg tjelesne mase) trajali 12 do 13 minuta. Kod primjene manje doze oporavak se mogao očekivati nakon pet minuta s povratkom EEG obrasca s α na β val, dok je kod većih doza α val trajao do 15 minuta. Pojava refleksa dizanja bila je zapažena nakon nestanka α valova. Učestalost srčanih otkucaja povećala se kod primjene obiju doza tijekom prvih pet minuta, a smanjila se nakon 10 i 15 minuta. Negativan T val bio je ustanovljen u dvije koze kod primjene manje doze, dok je kod primjene veće doze on bio ustanovljen u tri koze. Jedna koza koja je dobila veću dozu pokazivala je tahikardiju s ektopičnim otkucajima od pete do sedme minute nakon indukcije. Apneja se prosječno javljala tijekom prvih 30 sekundi kod primjene manje doze, a tijekom 42 sekunde kod primjene veće doze. U jedne koze apneja je pri primjeni veće doze bila zabilježena tijekom 314 sekundi. Toj je kozi za buđenje dano umjetno disanje nakon 106 sekundi te ponovljeno nakon 296 sekundi. Životinje su pokazivale težak dišni poremećaj s trbušnim disanjem u tijeku prvih nekoliko sekundi. Vrijednosti su se vratile na normalu nakon 15 minuta. Rezultati pokazuju da propofol smanjuje dišnu aktivnost u koza te je nužno primijeniti ventilaciju s pozitivnim tlakom. On ne dovodi do gubitka osjeta boli te treba primijeniti analgetike

Dexamethasone protected human glioblastoma U87MG cells from temozolomide induced apoptosis by maintaining Bax:Bcl-2 ratio and preventing proteolytic activities

BACKGROUND: Glioblastoma is the deadliest and most prevalent brain tumor. Dexamethasone (DXM) is a commonly used steroid for treating glioblastoma patients for alleviation of vasogenic edema and pain prior to treatment with chemotherapeutic drugs. Temozolomide (TMZ), an alkylating agent, has recently been introduced in clinical trials for treating glioblastoma. Here, we evaluated the modulatory effect of DXM on TMZ induced apoptosis in human glioblastoma U87MG cells. RESULTS: Freshly grown cells were treated with different doses of DXM or TMZ for 6 h followed by incubation in a drug-free medium for 48 h. Wright staining and ApopTag assay showed no apoptosis in cells treated with 40 μM DXM but considerable amounts of apoptosis in cells treated with 100 μM TMZ. Apoptosis in TMZ treated cells was associated with an increase in intracellular free [Ca(2+)], as determined by fura-2 assay. Western blot analyses showed alternations in the levels of Bax (pro-apoptotic) and Bcl-2 (anti-apoptotic) proteins resulting in increased Bax:Bcl-2 ratio in TMZ treated cells. Western blot analyses also detected overexpression of calpain and caspase-3, which cleaved 270 kD α-spectrin at specific sites for generation of 145 and 120 kD spectrin break down products (SBDPs), respectively. However, 1-h pretreatment of cells with 40 μM DXM dramatically decreased TMZ induced apoptosis, decreasing Bax:Bcl-2 ratio and SBDPs. CONCLUSION: Our results revealed an antagonistic effect of DXM on TMZ induced apoptosis in human glioblastoma U87MG cells, implying that treatment of glioblastoma patients with DXM prior to chemotherapy with TMZ might result in an undesirable clinical outcome

A comparative study on total phenolic content, reducing power and free radical scavenging activity of aerial parts of Barleria prionitis

Context: Barleria prionitis L. (Family Acanthaceae; commonly known as Vajradanti), is an annual shrub, 1–3 feet high, found throughout tropical Asia and in South Africa.Objective: The aim of the present study was to evaluate the antioxidant activity of 50% ethanolic extract of leaf, flower, and stem of B. prionitis by using β carotene bleaching assay, reducing power and free radical scavenging activity (DPPH and hydroxyl radical scavenging activity). Total phenolic content (TPC) was analysed by the Folin–Ciocalteu colorimetric method using gallic acid as standard and expressed as mg/g gallic acid equivalent (GAE).Results: Total phenolic content (TPC) and antioxidant activity (AOA) in B. prionitis leaves were found to be 67.48 mg/g GAE dry plant material and 79.20%. The B. prionitis leaves exhibited strong free radical scavenging activity as evidenced by the low IC50 values in both DPPH (1,1-diphenyl-2-picryl hydrazyl) (336.15 μg/ml) and hydroxyl radical (568.65 μg/ml) methods.Conclusions: The leaf of B. prionitis possesses high phenolic content, potential antioxidant activity, reducing power & radical scavenging activity in comparison to flower and stem.Keywords: Barleria prionitis, total phenolic content, β carotene bleaching assay, reducing power, free radical scavenging activity

Eleketroencefalografski pokazatelji za vrijeme anestezije propofolom i ksilazin-ketaminom u koza

The use of intravenous anaesthesia for short term surgical procedures in animal husbandry practices is increasing. However, information on the quality of an anaesthetic regime in goats has remained inadequate. Therefore, electroencephalographic studies were conducted on twelve apparently healthy adult female Barbari crossbred goats, aged 2 to 4 years, to assess the anaesthetic quality of a propofol and xylazine-ketamine combination. Quantitative analysis of EEG parameters [Total power, Median Frequency, Spectral Edge Frequency 90 (SEF-90) and Relative Power (RP) of different frequency bands delta (δ), theta (θ), alpha (α) and beta (β)] were assessed pre-experimentally (control), and at one, five, 10, 30 min, one hr, and two hr after intravenous propofol (4 mg/kg) and xylazine (0.05 mg/kg)-ketamine (4 mg/kg) administration. After propofol and xylazine-ketamine administration total power, RP-δ and θ increased significantly (P<0.05) while SEF 90, MF, RP-α and RP-β decreased. Most of the EEG changes were adequately depicted in vertex and parietal channels. Spectral analysis of EEG tracings suggested that propofol produced minimum anaesthetic stress and is a safer and better choice for short term anaesthesia in goats.U stočarskoj praksi se za kratkotrajne kirurške zahvate sve više primjenjuje intravenska anestezija. Nedostaju međutim podaci na temelju kojih bi se ustanovila kvaliteta anestezijskog protokola u koza. Kako bi se procijenila kvaliteta kombinacije anestetika propofola i ksilazin-ketamina, provedena je analiza elektoencefalografskih pokazatelja u 12 zdravih odraslih koza. Koze su bili križanci barbari pasmine u dobi od 2 do 4 godine. Kvantitativna analiza EEG pokazatelja (total power, median frequency, SEF-90, relative power delta-δ, theta-θ, alfa-α i beta-β frekvencijskih pojaseva) procijenjeni su prije pokusa (kontrolna skupina), te 1, 5, 10, 30 minuta, jedan sat i dva sata nakon intravenske primjene propofola (4 mg/kg) i ksilazin (0,05 mg/kg)-ketamina (4 mg/kg). Nakon primjene propofola i ksilazin-ketamina total power, te relative power-δ i relative power-θ znakovito su porasli (P < 0,05), dok su se SEF 90, median frequency, relative power-α i relative power-β snizili. Većina EEG promjena odgovarajuće je prikazana u verteksu i parijetalnim kanalima. Spektralna analiza EEG-a upućuje na to da propofol u anestezijskom protokolu uzrokuje minimalan stres te je, u usporedbi sa ksilazin-ketaminom, za kratkotrajnu anesteziju koza sigurniji i bolji izbor

Probing a ferromagnetic critical regime using nonlinear susceptibility

The second order para-ferromagnetic phase transition in a series of amorphous alloys (Fe{_5}Co{_{50}}Ni{_{17-x}}Cr{_x}B{_{16}}Si{_{12}}) is investigated using nonlinear susceptibility. A simple molecular field treatment for the critical region shows that the third order suceptibility (chi{_3}) diverges on both sides of the transition temperature, and changes sign at T{_C}. This critical behaviour is observed experimentally in this series of amorphous ferromagnets, and the related assymptotic critical exponents are calculated. It is shown that using the proper scaling equations, all the exponents necessary for a complete characterization of the phase transition can be determined using linear and nonlinear susceptiblity measurements alone. Using meticulous nonlinear susceptibility measurements, it is shown that at times chi{_3} can be more sensitive than the linear susceptibility (chi{_1}) in unravelling the magnetism of ferromagnetic spin systems. A new technique for accurately determining T{_C} is discussed, which makes use of the functional form of chi{_3} in the critical region.Comment: 11 Figures, Submitted to Physical Review