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2.
Microsyst Nanoeng ; 9: 34, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36969965

RESUMO

We report a non-resonant piezoelectric microelectromechanical cantilever system for the measurement of liquid viscosity. The system consists of two PiezoMEMS cantilevers in-line, with their free ends facing each other. The system is immersed in the fluid under test for viscosity measurement. One of the cantilevers is actuated using the embedded piezoelectric thin film to oscillate at a pre-selected non-resonant frequency. The second cantilever, the passive one, starts to oscillate due to the fluid-mediated energy transfer. The relative response of the passive cantilever is used as the metric for the fluid's kinematic viscosity. The fabricated cantilevers are tested as viscosity sensors by carrying out experiments in fluids with different viscosities. The viscometer can measure viscosity at a single frequency of choice, and hence some important considerations for frequency selection are discussed. A discussion on the energy coupling between the active and the passive cantilevers is presented. The novel PiezoMEMS viscometer architecture proposed in this work will overcome several challenges faced by state-of-the-art resonance MEMS viscometers, by enabling faster and direct measurement, straightforward calibration, and the possibility of shear rate-dependent viscosity measurement.

3.
Indian J Psychiatry ; 64(6): 540-544, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36714664

RESUMO

There is limited research in India focusing on the criminal justice system issues involving a special category of victims and accused suffering from unsoundness of mind. According to the Mental Health Care Act, 2017, they need immediate mental health services, as denial of the same is a violation of their fundamental right. Despite several advancements, people with unsound mind serving their sentences in the prisons constitute a major lot of the total prison population in India, despite the fact that they are the most helpless targets of human rights violations. Section 84 of the Indian Penal Code provides a constitutional right to an accused with unsound mind to seek defense against prosecution; but due to lack of awareness and acceptance and also due to outdated testing methods, the law is not under frequent practice and not exercised to its complete worth. By compromising on the procedure established by law, they are kept under trial in judicial custody. Thus, there is an urgent need to identify and address such victims and provide them with right care and protection that the constitution entitles them. This review article is an attempt to explore and highlight this issue, to raise a voice for identification of such violations, to provide means to deliberate medicolegal aid, and lastly to find out probable solutions, recommendations, and suggestions for a better administration of justice by providing legal security to the protection of basic human rights of people with an unsound mind.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31794394

RESUMO

A linear piezoelectric micromachined ultrasound transducer (PMUT) array was fabricated and integrated into a device for photoacoustic imaging (PAI) of tissue phantoms. The PMUT contained 65 array elements, with each element having 60 diaphragms of [Formula: see text] diameter and [Formula: see text] pitch. A lead zirconate titanate (PZT) thin film was used as the piezoelectric layer. The in-air vibration response of the PMUT array elements showed a first mode resonance between 6 and 8 MHz. Hydrophone measurements showed 16.2 kPa average peak ultrasound pressure output at 7.5 mm from one element excited with 5 Vpp input. A receive sensitivity of ~0.48 mV/kPa was observed for a PMUT array element with 0 dB gain. The PMUT array was bonded to a custom-printed circuit board to enable compact integration with an optical fiber bundle for PAI. A broad photoacoustic bandwidth of ~89% was observed for the photoacoustic response captured from absorbing pencil lead targets. Linear scanning of a single element of a PMUT array was performed on different tissue phantoms embedded with light-absorbing targets to successfully demonstrate B-mode PAI using PMUTs.


Assuntos
Microtecnologia/instrumentação , Técnicas Fotoacústicas/instrumentação , Ultrassonografia/instrumentação , Desenho de Equipamento , Sistemas Microeletromecânicos/instrumentação , Imagens de Fantasmas , Transdutores
5.
IEEE Trans Ultrason Ferroelectr Freq Control ; 66(10): 1606-1615, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31283502

RESUMO

Lead zirconate titanate (PZT)-based piezoelectric micromachined ultrasonic transducers (PMUTs) for particle manipulation applications were designed, fabricated, characterized, and tested. The PMUTs had a diaphragm diameter of 60 [Formula: see text], a resonant frequency of ~8 MHz, and an operational bandwidth (BW) of 62.5%. Acoustic pressure output in water was 9.5 kPa at 7.5 mm distance from a PMUT element excited with a unipolar waveform at 5 Vpp . The element consisted of 20 diaphragms connected electrically in parallel. Particle trapping of 4 [Formula: see text] silica beads was shown to be possible with 5 Vpp unipolar excitation. Trapping of multiple beads by a single element and deterministic control of particles via acoustophoresis without the assistance of microfluidic flow were demonstrated. It was found that the particles move toward diaphragm areas of highest pressure, in agreement with literature and simulations. Unique bead patterns were generated at different driving frequencies and were formed at frequencies up to 60 MHz, much higher than the operational BW. Levitation planes were generated above the 30 MHz driving frequency.

6.
Proc IEEE Sens ; 20182018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31303903

RESUMO

In this work, the design, fabrication, and characterization of piezoelectric micromachined ultrasound transducer (PMUT) arrays for photoacoustic imaging applications are reported. An 80-element linear PMUT array with each element having 53 PMUT cells of 125 µm cell diameter were fabricated using 650 nm thick lead zirconate titanate (PZT) as the active piezoelectric layer. The PMUTs are designed to operate at ~10 MHz resonant frequency. The PMUT elements are validated for photoacoustic imaging using an agar gel phantom with embedded pencil leads as the imaging target. Photoacoustic A-line response of the targets captured by single PMUT element shows ~7 MHz center frequency with ~4.8 MHz bandwidth. B-mode images reconstructed from A-lines recorded during the linear scanning of a single element clearly imaged all the targets, thus validating the potential of the fabricated PMUTs for photoacoustic imaging.

7.
ScientificWorldJournal ; 2012: 291395, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22666103

RESUMO

Laboratory evaluations were made to assess the toxicological and biochemical effect of cypermethrin on fingerlings of common edible freshwater culture carp (Labeo rohita). There was a significant negative (P < 0.05) correlation observed between effective doses of cypermethrin and exposure periods; that is, LC50 values decreased from 0.323 µg/L (6 h) to > 0.278 µg/L (12 h), > 0.240 µg/L (18 h) and >0.205 µg/L (24 h). Exposure to sublethal doses of cypermethrin for 24 h and 96 h exposure period caused significant (P < 0.05) time- and dose-dependent alterations in total protein, total free amino acids, nucleic acids, glycogen, pyruvate, and lactate level and in the activity of enzyme protease, alanine aminotransferase, aspartate aminotransferase, acid phosphatases, alkaline phosphatases, acetylcholinesterase, and cytochrome oxidase in liver and muscle tissues of fish. Thus, cypermethrin has potent piscicidal activity against fingerlings of fish Labeo rohita and adversely affects their behavioural patterns, shifting aerobic pathway of fish respiration towards anaerobic pathway and also inhibiting energy production by suppressing ATP synthesis.


Assuntos
Carpas/crescimento & desenvolvimento , Inseticidas/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais
8.
Afr J Tradit Complement Altern Med ; 5(4): 332-9, 2008 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20161954

RESUMO

Cycloart-24-en-3beta-ol isolated from Euphorbia royleana latex possesses potent piscicidal activity against freshwater predatory fish Channa punctatus. Their short as well as long-term exposure causes significant (P<0.05) time and dose-dependent reversible alteration in the oxidative metabolism of the fish Channa punctatus Cycloart-24-en-3beta-ol also shifts fish respiratory pathway, inhibits energy production and AChE activity reversibly may be advantageous for their use as environmentally safe piscicide for controlling the predatory fish C. punctatus population from carp culture ponds.

9.
Chemosphere ; 64(1): 36-42, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16423380

RESUMO

Piscicidal activities of aqueous extracts of Euphorbia tirucalli were very well established, but their ultimate mode of action on fish metabolism was not yet known. Exposure of fishes over 24h or 96h to sub-lethal doses (40% and 80% of LC(50)) of aqueous extract of E. tirucalli stem-bark and latex, significantly (P<0.05) altered the level of total protein, total free amino acids, nucleic acids, glycogen, pyruvate, lactate and activity of protease, alanine aminotransferase, aspartate aminotransferase, acetylcholinesterase and cytochrome oxidase enzyme in liver and muscle tissues of freshwater fish Channa punctatus. The alterations in all these biochemical parameters were significantly (P<0.05) time- and dose-dependent. After 7d of withdrawal of treatment of 80% of LC(50) of E. tirucalli extracts shows that there was a partial recovery in the levels of glycogen but nearly complete recovery in total protein, total free amino acids, pyruvate, lactate, nucleic acids level and activity of protease, aspartate aminotransferase, alanine aminotransferase, acetylcholinesterase and cytochrome oxidase enzyme in both the tissues of fish. Thus aqueous extracts of E. tirucalli adversely affect respiratory pathway of fish and cause energy crisis during stress by suppressing ATP production. The reversibility of the action of the aqueous extracts would be an additional advantage in their use.


Assuntos
Euphorbia/química , Perciformes/metabolismo , Extratos Vegetais/toxicidade , Acetilcolinesterase/metabolismo , Alanina Transaminase/metabolismo , Aminoácidos/análise , Animais , Aspartato Aminotransferases/metabolismo , DNA/análise , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Glicogênio/análise , Ácido Láctico/análise , Látex/química , Fígado/metabolismo , Músculos/metabolismo , Peptídeo Hidrolases/metabolismo , Caules de Planta/química , Proteínas/análise , Ácido Pirúvico/análise , RNA/análise , Água/química
10.
Environ Res ; 99(3): 378-86, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16307980

RESUMO

To know the short- as well as long-term effect of aqueous latex extracts of Euphorbia tirucalli on carbohydrate and protein metabolism, the snail Lymnaea acuminata was exposed to sublethal doses of 0.37 and 0.55 mg/L for a 24-h and 0.20 and 0.31 mg/L for a 96-h exposure period. Significant (P<0.05) alterations in the glycogen, pyruvate, lactate, total protein, and free amino acid level, as well as in the activity of enzyme lactic dehydrogenase, succinic dehydrogenase, cytochrome oxidase, protease, aspartate aminotransaminase, and alanine aminotransaminase were observed in the nervous, hepatopancreatic, and ovotestis tissues of the freshwater vector snail L. acuminata exposed to sublethal doses of E. tirucalli latex extract. The alterations in all biochemical parameters were significantly (P<0.05) time and dose dependent. After the 7th day of the withdrawal of treatment, there was significant (P<0.05) recovery in glycogen, pyruvate, lactate, total protein, and the free amino acid level and in the activity of the lactic dehydrogenase, succinic dehydrogenase, cytochrome oxidase, protease, aspartate aminotransaminase and alanine aminotransaminase enzymes in all three of the studied tissues of the snail, which supports the view that the plant product is safe for use as a molluscicide for the control of harmful freshwater vector snails in the aquatic environment.


Assuntos
Metabolismo dos Carboidratos , Euphorbia/química , Lymnaea/metabolismo , Controle de Pragas , Proteínas/metabolismo , Animais , Fasciolíase/transmissão , Lymnaea/parasitologia , Extratos Vegetais/farmacologia
11.
Chemosphere ; 59(2): 263-70, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15722098

RESUMO

The aqueous stem bark and leaf extracts of plant Euphorbia hirta (family-Euphorbiaceae) have potent molluscicidal activity. Sub-lethal doses (40% and 80% of LC50) of aqueous stem bark and leaf extracts of this plant also significantly (P<0.05) alter the levels of total protein, total free amino acid, nucleic acids (DNA and RNA) and the activity of enzyme protease and acid and alkaline phosphatase in various tissues of the vector snail Lymnaea acuminata in time and dose dependent manner. Euphorbia hirta (family-Euphorbiaceae) commonly known as Dudhi, is a common medicinal plant of India, which is used in variety of diseases i.e. cough, asthma, colic, dysentery, genito urinary diseases.


Assuntos
Euphorbia , Casca de Planta/toxicidade , Folhas de Planta/toxicidade , Caramujos/efeitos dos fármacos , Aminoácidos/metabolismo , Animais , Relação Dose-Resposta a Droga , Água Doce , Índia , Dose Letal Mediana , Ácidos Nucleicos/metabolismo , Peptídeo Hidrolases/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Extratos Vegetais/toxicidade , Proteínas de Plantas/metabolismo , Caramujos/metabolismo , Fatores de Tempo
12.
Indian J Exp Biol ; 42(12): 1220-5, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15623235

RESUMO

Laboratory evaluation was made to assess the molluscicidal activity of different fractions of Euphorbia royleana (Family- Euphorbiaceae) latex obtained through sephadex gel column against freshwater snail Lymnaea (Radix) acuminata Lamarack. This snail is the vector of liver fluke, Fasciola hepatica Linnaeus and Fasciola gigantica Cobbold, which causes endemic fascioliasis in cattle and livestock. The toxic effect of the different fractions was time dependent and fifth fraction obtained through benzene: ethyl acetate (5:5) had maximum molluscicidal activity against Lymnaea acuminata. There was a significant negative correlation between LC values and exposure periods thus increase in exposure time, the LC50 value of V fraction of Euphorbia royleana latex was decreased from 14.28 mg/l (24 hr) to 9.28 mg/l (96 hr) against Lymnaea acuminata. After exposure to sub-lethal concentrations of this fraction there were significant time and dose dependent alterations observed in pyruvate, lactate levels, ALAT, AAT, AChE and cytochrome oxidase enzyme activities in different body tissues of Lymnaea acuminata. It is proposed that the fifth fraction of E. royleana latex can be used as a molluscicide for controlling the harmful snail population from aquatic ecosystem without any harm due to their reversible toxic action.


Assuntos
Euphorbia/química , Lymnaea/efeitos dos fármacos , Lymnaea/metabolismo , Moluscocidas/farmacologia , Animais , Vetores de Doenças , Ácido Láctico/metabolismo , Látex/farmacologia , Lymnaea/parasitologia , Extratos Vegetais/farmacologia , Ácido Pirúvico/metabolismo
13.
Indian J Exp Biol ; 42(4): 413-8, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15088692

RESUMO

Active compound oleandrin extracted from Nerium indicum (Lal Kaner) leaf has potent piscicidal activity. The piscicidal activity of oleandrin on freshwater fish C. punctatus was both time and dose dependent. Exposure to sub-lethal doses of oleandrin for 24hr and 96hr to fish caused significant alteration in the level of total protein, total free amino acid, nucleic acid, glycogen, pyruvate, lactate and enzyme protease, phosphatases, alanine aminotransferase, aspartate aminotransferase and acetylcholinesterase activity in liver and muscle tissues. The alterations in all the above biochemical parameters were also significantly time and dose dependent. The results show a significant recovery in all the above biochemical parameters, in both liver and muscle tissues of fish after the 7th day of the withdrawal of treatment. Toxicity persistence test of oleandrin on juvenile Labeo rohita shows that fish seed of common culturing carp can be released into rearing ponds after three days of oleandrin treatment. It supports the view that the oleandrin is safer and may be useful substitute of other piscicides for removing the unwanted freshwater fishes from aquaculture ponds.


Assuntos
Cardenolídeos/toxicidade , Glicosídeos Cardíacos/toxicidade , Fígado/efeitos dos fármacos , Músculos/efeitos dos fármacos , Perciformes/fisiologia , Acetilcolinesterase/metabolismo , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Cardenolídeos/química , Glicosídeos Cardíacos/química , Relação Dose-Resposta a Droga , Glicogênio/metabolismo , Índia , Ácido Láctico/metabolismo , Dose Letal Mediana , Fígado/química , Fígado/metabolismo , Músculos/química , Músculos/metabolismo , Extratos Vegetais/toxicidade , Folhas de Planta/toxicidade , Ácido Pirúvico/metabolismo
14.
Environ Toxicol Pharmacol ; 18(1): 47-53, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21782734

RESUMO

The present paper deals with the piscicidal activity of different solvent extracts of Euphorbia royleana stem bark against freshwater predatory fish Channa punctatus, which is commonly present in shrimp and carp culture ponds. The rank of order of toxicity of different solvent extract was: diethyl ether (LC(50) (96h) 31.76mg DW/L) > chloroform (LC(50) (96h) 56.26mg DW/L) > methanol (LC(50) (96h) 56.80mg DW/L) > acetone (LC(50) (96h) 65.77mg DW/L). There was a significant (P < 0.05) negative correlation between LC values and exposure periods, thus increase in exposure time. The LC(50) values of diethyl ether extract of E. royleana stem bark decrease from 81.78mg DW/L (24h) to 31.76mg DW/L (96h). Similar trend were also observed in case of chloroform, methanol and acetone extracts. Exposure of sub-lethal doses (40% and 80% of LC(50)) of the diethyl ether extract for 24h or 96h caused significant inhibition in the activity of enzyme acetylcholinesterase (AChE) in liver and muscle tissue of fish C. punctatus. There was a significant recovery observed in the activity of enzyme acetylcholinesterase in both the tissues of fish after 7th day of the withdrawal of treatment. Thus, the diethyl ether extract of E. royleana stem bark can be used for control of unwanted predatory fish C. punctatus from fish culture ponds. Their toxicological action is due to their anti-acetylcholinesterase enzyme activity, reversibility in their action is advantageous factor for their use as environmentally safe piscicide in aquatic bodies.

15.
Chemosphere ; 53(8): 865-75, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14505708

RESUMO

The diethyl ether, chloroform, acetone and methanol extract of Nerium indicum leaf were evaluated for their piscicidal activity against common freshwater air breathing predatory fish Channa punctatus. The rank of order of toxicity (LC50) of the leaf extract was, diethyl ether extract (17.34 mg/l)>acetone (40.01 mg/l)>chloroform (40.61 mg/l)>and methanol (106.37 mg/l). There was a significant negative correlation between LC50 values and exposure periods. Thus increase in exposure period, LC50 decreases from 17.34 mg/l (24 h) to >13.58 mg/l (96 h) in the diethyl ether extract. Similar trends were also observed in acetone, chloroform and methanol extracts. Exposure of sub-lethal doses (40% and 80% of LC50) of the diethyl ether extract of N. indicum leaf (which has maximum piscicidal activity) for 24 or 96 h caused significant alteration in the level of total protein, total free amino acid, nucleic acid, glycogen, pyruvate, lactate and activity of enzyme protease, phosphatases, alanine aminotransferase, aspartate aminotransferase and acetylcholinesterase in liver and muscle tissue. The alterations in all the above biochemical parameters were significantly (P<0.05) time and dose dependent. There was a significant recovery in all the above biochemical parameters, in both liver and muscle tissues of fish after the seventh day of the withdrawal of treatment. Thus, the leaf extracts of N. indicum have potent piscicidal activity against fish C. punctatus and also significantly affect both aerobic and anaerobic pathway of respiration in fish.


Assuntos
Fígado/efeitos dos fármacos , Músculos/efeitos dos fármacos , Nerium/toxicidade , Perciformes/fisiologia , Animais , Relação Dose-Resposta a Droga , Índia , Dose Letal Mediana , Fígado/química , Músculos/química , Nerium/química , Perciformes/metabolismo , Extratos Vegetais/toxicidade , Folhas de Planta/toxicidade , Fatores de Tempo
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