Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Morphologie ; 106(355): 235-240, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34479815

RESUMO

OBJECTIVE: We aimed to explore to what extent the literature supports that the use of cadaveric computed tomography can play an important role in anatomy education. MATERIALS AND METHODS: PubMed, SCOPUS, Education Resources Information Center and Cochrane Databases were searched for papers with purpose to explore the outcomes of the use of cadaveric computed tomography scans in anatomy education. The following data were obtained from each paper: authors, number of participants, type of study (comparative or not), level of outcome according to Kirkpatrick hierarchy, possible evaluation of statistical significance, acquisition of anatomical knowledge after the educational intervention and perceptions about the effectiveness of this intervention in anatomy learning. RESULTS: Seven articles were included. Four of them evaluated students' knowledge after the use of cadaveric computed tomography scans in anatomy education and three papers evaluated only students' perceptions. Generally, the outcomes, which mainly concerned students' perceptions, were positive, while it was showed that students' academic performance may also be improved. CONCLUSIONS: The outcomes of the use of cadaveric computed tomography scans in anatomy education encourage the implementation of this teaching modality in anatomy curricula. Further research, including comparative studies with evaluation of acquisition of students' knowledge, is needed to show if cadaveric computed tomography will be proved a remarkable supportive tool in anatomy educators' hands.


Assuntos
Anatomia , Educação de Graduação em Medicina , Estudantes de Medicina , Humanos , Educação de Graduação em Medicina/métodos , Aprendizagem , Currículo , Tomografia Computadorizada por Raios X , Cadáver , Anatomia/educação
2.
Surg Radiol Anat ; 43(3): 327-345, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33386933

RESUMO

INTRODUCTION: Typical branching pattern of the left-sided aortic arch consists of the brachiocephalic trunk (BCT), the left common carotid artery (LCCA) and the left subclavian artery (LSA). Variant patterns have been associated with a broad spectrum of pathologies. The meticulous knowledge of potential aortic arch variants is of utmost importance to radiologists, interventional cardiologists, vascular and thoracic surgeons. The current systematic review collects all aortic arch branching patterns and their frequency as published by various cadaveric studies, calculates prevalence taking into account the gender and the different people background, as well. All extracted variant patterns are classified into types and subtypes according to the number of emerging (major and minor) branches (1, 2, 3, 4 and 5) and to the prevalence they appear. In cases of similar prevalence, total cases were taken into consideration; otherwise the variants were classified under the title "other rare variants". METHODS: A systematic online search of PubMed and Google books databases was performed only in cadaveric studies. RESULTS: Twenty studies with typical (78% prevalence) and variable (22%) branching patterns were included. Types 3b, 2b, 4b, 1b and 5b had a prevalence of 81%, of 13%, of 5%, 0% and of 0%, respectively. Common variants were the brachiocephalico-carotid trunk (BCCT, 49% prevalence), the aberrant left vertebral artery (LVA, 41%) and the aberrant right subclavian artery (ARSA, 8%). LVA of aortic origin was detected in 32%, the bicarotid trunk (biCT) in 5% and the bi-BCT trunk in 3%. Thyroidea ima artery, a minor branch emerging from the aortic arch was found in 2%. Coexisted variants were detected in 4% (ARSA with a distinct RCCA and LCCA origin), in 3% (BCCT with a LVA of aortic origin), in 2% (ARSA with a biCT and a vertebrosubclavian trunk). CONCLUSION: No significant gender or ethnic differences exist among the 5 branching types. The proposed classification scheme aims to become a valuable and easy to use tool in the hands of all physicians involved in diagnosis and treatment of aortic arch pathology. It could be also useful in anatomical education, as well.


Assuntos
Variação Anatômica , Aorta Torácica/anatomia & histologia , Tronco Braquiocefálico/anatomia & histologia , Artéria Carótida Primitiva/anatomia & histologia , Artéria Subclávia/anatomia & histologia , Cadáver , Feminino , Humanos , Masculino , Prevalência , Fatores Sexuais
3.
Surg Radiol Anat ; 40(3): 313-322, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29124342

RESUMO

PURPOSE: Although communications between branches and cords of the brachial plexus have been extensively published, there is a scarcity of reports concerning radial and ulnar nerve (RN-UN) communication in the arm. The current study aims to demonstrate the incidence, topography, and length of communicating branches between RN and UN. Any additional coexisted variations were also recorded. MATERIALS AND METHODS: Two hundred and sixty-six upper limbs collected from one hundred and thirty-three (81 males and 52 females) Greek cadavers were dissected. RESULTS: Three out of one hundred and thirty-three cadavers, accounting for an incidence of up to 2.3%, were found to have an atypical communicating branch originating at a high humeral level from RN towards UN. In two cadavers, communicating branches were detected on the left side and in one cadaver bilaterally. CONCLUSIONS: The study of atypical communications between RN and UN attracts great attention for its clinical importance, mainly in cases of peripheral neuropathies with diagnostic dilemma or upper limb nerve injury producing an otherwise unexpected symptomatology due to the aberrant nerve supply. Familiarity with these variations is crucial in avoiding misdiagnosis and preserving valuable communicating branches, thus achieving an uneventful outcome in cases of upper limb nerve injury repair.


Assuntos
Úmero/inervação , Nervo Radial/anatomia & histologia , Nervo Ulnar/anatomia & histologia , Variação Anatômica , Cadáver , Dissecação , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade
4.
Morphologie ; 102(337): 83-86, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29496384

RESUMO

A three-headed anterior belly of the digastric muscle (ABDM) on the right side of a 54-year old Greek male cadaver coexisted with two accessory muscle bundles (AMB) in the submental region. The left ABDM was typical. Typical ABDM was attached to the digastric fossa, while the accessory right anterior bellies to the lower border of the mandible. A muscle bundle arising from the attachment of the left ABDM to the hyoid bone was also observed fusing with the AMB of the ipsilateral side. It is of extreme importance to be aware of the submental region anatomical variations during surgery, imaging interpretation or differential diagnosis of neck masses.


Assuntos
Variação Anatômica , Músculos do Pescoço/anormalidades , Cadáver , Humanos , Osso Hioide/anatomia & histologia , Masculino , Mandíbula/anatomia & histologia , Pessoa de Meia-Idade
5.
Folia Morphol (Warsz) ; 75(1): 130-135, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26383509

RESUMO

A 37-year-old female Caucasian cadaver with an aberrant right subclavian artery extending from the left side of the aortic arch and following a retro-oesophageal course is presented. A non-recurrent right laryngeal nerve and a thyroid ima artery arising from the lower part of the middle third of the right common carotid artery coexisted. The brachiocephalic trunk was absent, while both common carotid arteries and left subclavian artery followed their normal course. The aim of the current study is to highlight the clinical impact of the above abnormalities providing useful and practically applicable knowledge to interventional clinicians, thoracic and neck surgeons, since the vast majority of documented cases with an arteria lusoria are clinically silent and in most cases discovered incidentally. Clinical manifestations such as dysphagia, chronic cough, and acute ischaemia to the right upper limb may occur, leading to misinterpretation in radiographic examination and complications during neck and thoracic surgery. Review of the literature was also performed and the embryological background of the aberration is highlighted.


Assuntos
Artéria Subclávia , Adulto , Aneurisma , Aorta Torácica , Anormalidades Cardiovasculares , Transtornos de Deglutição , Feminino , Humanos
6.
Folia Morphol (Warsz) ; 75(4): 481-485, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27830881

RESUMO

BACKGROUND: The course of the infrapatellar branch of saphenous nerve (IPBSN) in relation to the Sartorius muscle has been classified into presartorial, transsartorial and retrosartorial types. Mechanical compression of the IPBSN within the Sartorius tendon has been surgically recognised as a cause of entrapment neuropathy. Purpose of the present study was to differentiate the IPBSNs penetrating the Sartorius tendon from those penetrating the Sartorius muscle, from an anatomical and clinical point of views and thus modifying the existing classification. MATERIALS AND METHODS: The IPBSN was bilaterally dissected in 27 cadavers. The cases of the IPBSNs penetrating the Sartorius tendon were recorded separately from those penetrating the Sartorius muscle belly. RESULTS: In 11 out of 54 limbs (20.4%) the IPBSN ran through the Sartorius muscle belly. In 3 out of 54 (5.6%) limbs, the IPBSN penetrated the Sartorius tendon. CONCLUSIONS: The penetrating type of IPBSN includes two distinct subtypes: the muscle-penetrating type and the tendon-penetrating type. These subtypes are also distinct from a clinical point of view, since only the tendon-penetrating type has been associated with the IPBSN entrapment neuropathy. According to these findings we suggest a modification of the current classification. Further clinical studies are necessary to fully demonstrate whether the tendon-penetrating type should be considered as a predisposing factor for the IPBSN entrapment neuropathy. Distinguishing the two subtypes might be helpful for that purpose.


Assuntos
Síndromes de Compressão Nervosa , Humanos , Joelho , Articulação do Joelho , Músculo Esquelético , Tendões
7.
J Laryngol Otol ; 136(12): 1170-1176, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36017719

RESUMO

OBJECTIVE: The aim of this systematic review was to analyse the complex anatomy of the extratemporal portion of the facial nerve with an accurate description of the branching patterns based on the Davis classification. METHOD: Medline, ScienceDirect and the Cochrane Library databases as well as other sources were searched by two independent reviewers. RESULTS: Analysis of 21 studies with a total of 1497 cases showed that type III is the most common branching pattern accounting for 26.8 per cent of cases. The type I pattern, previously considered as the normal anatomy in most textbooks, was the fourth most common branching pattern at 16.3 per cent. The majority of specimens (96.4 per cent) were found to have a bifurcated main trunk, and only 3.2 per cent were found with a trifurcated main trunk. CONCLUSION: Surgeons should be aware of anatomical variations in the course of the facial nerve. An early identification of the branching pattern during surgery reduces the risk for iatrogenic facial nerve injury.


Assuntos
Traumatismos do Nervo Facial , Nervo Facial , Humanos , Traumatismos do Nervo Facial/prevenção & controle , Cadáver , Glândula Parótida
8.
Folia Morphol (Warsz) ; 80(4): 994-1004, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32896866

RESUMO

BACKGROUND: Pterion is the junction of the frontal, parietal, greater wing of the sphenoid and the squamous part of the temporal bone. The sphenoparietal, frontotemporal, stellate and epipteric pteria were described. The current study determines pterion topography, morphology (variant types' frequency) and morphometry, as well as epipteric bones presence in dried skulls. Gender impact is underlined as well. MATERIALS AND METHODS: Ninety Greek adult dried skulls were observed. The distances in between pterion and the zygomatic arch midpoint and in between pterion and the frontozygomatic suture were measured. RESULTS: The sphenoparietal pterion was the commonest (58.3%), following by the stellate (25%), epipteric (15.5%) and by the frontotemporal pterion (1.1%). Twenty-eight (15.5%) skulls had epipteric bones, further categorised as quadrisutural (35.7%), trisutural (57.1%), bisutural and multiple (3.57%). The mean distances between pterion and the midpoint of zygomatic arch were 4.13 ± 0.45 cm on the right and 4.09 ± 0.47 cm on the left side and between pterion and the frontozygomatic suture were 3.47 ± 0.61 cm on the right and 3.52 ± 0.65 cm on the left side. Both distances were symmetrical. Male skulls showed slightly higher values on the left side for the distance (pterion-midpoint of zygomatic arch). CONCLUSIONS: Pterion is a commonly used neurosurgical landmark and thus in depth knowledge of the pteric area and its variants could be valuable. Recognition of the possible variability in pterion location, morphology and morphometry, as well as possible occurrence of epipteric bones may render pterional craniotomy safer among different population groups.


Assuntos
Suturas Cranianas , Zigoma , Humanos , Conhecimento , Masculino , Osso Esfenoide , Osso Temporal
9.
Folia Morphol (Warsz) ; 68(4): 193-200, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19950066

RESUMO

The median artery usually regresses after the eighth week of intrauterine life, but in some cases it persists into adulthood. The persistent median artery (PMA) passes through the carpal tunnel of the wrist, accompanying the median nerve. During anatomical dissection in our department, we found two unilateral cases of PMA originating from the ulnar artery. In both cases the PMA passed through the carpal tunnel, reached the palm, and anastomosed with the ulnar artery, forming a medio-ulnar type of superficial palmar arch. In addition, in both cases we observed a high division of the median nerve before entering the carpal tunnel. Such an artery may result in several complications such as carpal tunnel syndrome, pronator syndrome, or compression of the anterior interosseous nerve. Therefore, the presence of a PMA should be taken into consideration in clinical practice. This study presents two cases of PMA along with an embryological explanation, analysis of its clinical significance, and a review of the literature. The review of the literature includes cases observed during surgical procedures or anatomical dissections. Cases observed by means of imaging techniques were not included in the study.


Assuntos
Artéria Axilar/anormalidades , Síndrome do Túnel Carpal/etiologia , Antebraço/irrigação sanguínea , Artéria Axilar/anatomia & histologia , Feminino , Humanos , Incidência , Masculino , Nervo Mediano/anatomia & histologia , Nervo Mediano/fisiopatologia , Pessoa de Meia-Idade , Artéria Radial/anatomia & histologia , Artéria Radial/embriologia , Artéria Ulnar/anatomia & histologia , Artéria Ulnar/embriologia
10.
Folia Morphol (Warsz) ; 78(2): 444-449, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30178460

RESUMO

Neural and vascular variations in the axilla and upper limb area are usually paired, but coexistence of muscular aberration on top of this is uncommon. The current case report emphasizes on the unilateral coexistence of a three-headed (tricipital) biceps brachii muscle, a two-headed coracobrachialis with an accessory muscle bundle joining the superficial and deep heads of coracobrachialis muscle. On the ipsilateral side of the 72-year-old male cadaver, a connecting branch originated from the musculocutaneous nerve and joined the median nerve after surpassing the accessory muscle bundle. A large diameter subscapular trunk originated from the 2nd part of the axillary artery and after giving off the 1st lateral thoracic artery trifurcated into a common stem which gave off the 2nd and 3rd lateral thoracic arteries, the circumflex scapular artery and a common branch that gave off the 4th and 5th lateral thoracic arteries and the thoracodorsal artery, as the ultimate branch. All lateral thoracic arteries were accompanied by multiple intercostobra- chial nerves. Documentation of such muscular and neurovascular variants and their embryologic origin increases awareness of their potential impact on diagnosis and treatment of upper limb pathology. To the best of our knowledge, the currently reported cadaveric observations seem to constitute a unique finding.


Assuntos
Músculo Esquelético/anormalidades , Músculo Esquelético/inervação , Idoso , Humanos , Masculino , Músculo Esquelético/irrigação sanguínea
11.
Folia Morphol (Warsz) ; 78(2): 359-370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30155873

RESUMO

BACKGROUND: Wormian bones (WBs) are irregularly shaped bones formed from independent ossification centres found along cranial sutures and fontanelles. Their incidence varies among different populations and they constitute an anthropo- logical marker. Precise mechanism of formation is unknown and being under the control of genetic background and environmental factors. The aim of the current study is to investigate the incidence of WBs presence, number and topographical distribution according to gender and side in Greek adult dry skulls. MATERIALS AND METHODS: All sutures and fontanelles of 166 Greek adult dry skulls were examined for the presence, topography and number of WBs. One hundred and nineteen intact and 47 horizontally craniotomised skulls were examined for WBs presence on either side of the cranium, both exocranially and intracranially. RESULTS: One hundred and twenty-four (74.7%) skulls had WBs. No difference was detected between the incidence of WBs, gender and age. Sutures and fon- tanelles located in neurocranium showed a higher incidence of WBs, contrariwise to orbital sutures that indicated a low incidence. WBs most commonly located in the lambdoid suture (44.6%), followed in order of frequency by the coronal suture (39.8%), asterion (21% on the left and 15.3% on the right side) and parie- tomastoid suture (15.1% on the left and 13.9% on the right side). Other sutures with WBs were the occipitomastoid, sagittal, squamosal, zygomaticosphenoid, metopic, frontonasal and frontozygomatic. Regarding the skull fontanelles, WBs were found at pterion, posterior and anterior fontanelles. CONCLUSIONS: The current study highlights a high incidence of WBs in a Greek population, indicating racial variation. The in depth knowledge of exact location, frequency and number of WBs is essential for clinicians intervening in the skull area, anthropologists and forensic surgeons investigating child abuse cases.


Assuntos
Crânio/anormalidades , Adulto , Suturas Cranianas/anormalidades , Feminino , Grécia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Water Res ; 39(18): 4385-96, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16233908

RESUMO

In this study, the removal of hexavalent and trivalent chromium ions from binary aqueous solutions by composite alginate-goethite beads was investigated in a batch mode. Equilibrium sorption experiments were carried out at different temperatures and pH values. The data were correlated with Langmuir and Freundlich equations. The thermodynamic parameters calculated were: change in free energy, in enthalpy, in entropy and the heat of adsorption. The influence of mixing rate, sorbent concentration and sorbent particle size was studied at kinetic runs. The effective diffusion coefficients were evaluated by employing the homogeneous diffusion model and the shrinking core model for hexavalent and trivalent chromium, respectively. Desorption experiments were conducted by employing various eluants showed that the loaded material could be regenerated satisfactorily.


Assuntos
Alginatos/química , Cromo/química , Compostos de Ferro/química , Poluentes Químicos da Água , Purificação da Água/métodos , Absorção , Cromo/análise , Difusão , Concentração de Íons de Hidrogênio , Cinética , Minerais , Soluções , Temperatura , Água/química , Poluentes Químicos da Água/análise
13.
Chemosphere ; 58(1): 65-73, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15522334

RESUMO

In this study, akaganeite (beta-FeO(OH)) an ironoxyhydroxide material, was used as a low-cost potential adsorbent for the removal of hexavalent chromium from aqueous solutions. The influence of agitation speed, solution pH, initial chromium concentration, sorbent concentration and temperature were evaluated at batch kinetic runs. It was shown that the solid diffusion model, in comparison to simple reaction kinetic models, described better the sorption kinetics. Freundlich and Frumkin isotherm best fitted the equilibrium results. Akaganeite presented a sorption capacity approximately 80 mg Cr(VI) g(-1), under the conditions studied. Flotation was used as a downstream process for the effective removal of the loaded material.


Assuntos
Cromo/química , Compostos Férricos/química , Poluição da Água/prevenção & controle , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Temperatura , Água/química
14.
Hippokratia ; 19(3): 263-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27418788

RESUMO

BACKGROUND: Varicose vein surgery is very commonly performed. Also, it is very frequently employed for recurrent disease. The recognition of the normal or variant veins, inducing incompetency, is a prerequisite for effective treatment. The thigh extension of the small saphenous vein, the so-called Giacomini vein, was extensively described in 1873 by Carlo Giacomini in an incidence of 72%. However, such a vein is usually underestimated in classic surgical textbooks. DESCRIPTION OF CASES: We present two cases of Giacomini vein found in two cadavers, dissected for academic purposes in the Department of Anatomy, where the small saphenous vein displayed a thigh extension without terminating into the popliteal vein. In one case Giacomini vein drained into the large saphenous vein, while in the other case the vein divided into two branches, separately draining into the large saphenous vein and the subcutaneous tissue of the gluteal region. CONCLUSION: Due to the fact that Giacomini vein could be incompetent, associated with or without varicose saphenous vein trunks, the vascular surgeon should keep in mind that anatomical entity, to include it in preoperative ultrasound scanning control. Moreover, this vein could be utilized as an autologous graft, when the large saphenous is not available. Hippokratia 2015; 19 (3): 263-265.

15.
Oral Oncol ; 39(7): 680-6, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12907207

RESUMO

Cancer of the anterior faucial pillar-retromolar trigone is an uncommon head and neck tumor, which has historically been shown to be associated with poor prognosis. In this retrospective study, we reviewed our experience with primary surgery followed by postoperative radiation therapy in order to determine the impact of our treatment protocols on patients' outcome. Between January 1994 and December 1998, 31 patients with histologically proven squamous cell carcinoma (SCC) of the anterior faucial pillar-retromolar trigone were treated in our department. Surgical excision of the primary lesion and ipsilateral neck dissection were performed in all patients. Reconstruction was accomplished using masseter muscle flap or tongue flap. Postoperatively, most patients (90%) received radiation therapy (51-58 Gy) to the primary side and neck. Adjuvant chemotherapy was offered if histologic signs of aggressive behavior were identified. Four out of 31 patients were initially seen at stage I or II and 27 patients at stage III or IV of the disease. Metastatic disease was demonstrated in 78% of ipsilateral neck nodes. Occult metastases were found in 64% of clinically N0 necks. The 3-year loco-regional recurrence rates were 44.8%. SCC of retromolar trigone is considered as an aggressive and insidious tumor. The reconstruction of the deficit of the anterior faucial pillar-retromolar area with masseter muscle flap is a reliable, safe and absolutely functional method.


Assuntos
Carcinoma de Células Escamosas/terapia , Neoplasias Bucais/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Terapia Combinada , Intervalo Livre de Doença , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Neoplasias Bucais/cirurgia , Esvaziamento Cervical , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Retalhos Cirúrgicos , Taxa de Sobrevida , Resultado do Tratamento
16.
Water Res ; 37(12): 2875-82, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12767290

RESUMO

The sorptive removal of hexavalent chromium from aqueous solutions by calcined Mg-Al-CO(3) hydrotalcite was investigated in a batch mode. The influence of agitation speed, solution pH, initial chromium concentration, sorbent concentration and temperature has been tested in kinetic runs. Three kinetic models have been evaluated to fit the experimental data: the pseudo-first order, the modified-second order and the Elovich equation. It was shown that the first-order model could best describe the sorption kinetics. A Freundlich isotherm was used to fit equilibrium experiments. Hydrotalcite presents a sorption capacity of approximately 120 mg Cr/g, under the investigated experimental conditions. The calculated activation energy for process studied was around 40 kJ/mol.


Assuntos
Hidróxido de Alumínio/química , Antiácidos/química , Carcinógenos Ambientais/química , Cromo/química , Hidróxido de Magnésio/química , Modelos Teóricos , Adsorção , Carcinógenos Ambientais/isolamento & purificação , Cromo/isolamento & purificação , Cinética , Temperatura
17.
Water Res ; 37(12): 3023-33, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12767306

RESUMO

The removal of a reactive color, Cibacron Yellow LS-R, from aqueous solutions by adsorption onto hydrotalcite particles is investigated using batch rate experiments. Measurements are performed at various initial color concentrations, solid loads, pH values and ionic backgrounds (dissolved NaCl). The speed of agitation and the temperature inside the batch adsorber are also varied within a practical range of values. It is shown that the sorption capacity is relatively high for most experimental conditions so hydrotalcite may be considered as a suitable sorbent for this application. The probable mechanism of the process is investigated by a number of homogeneous and heterogeneous reaction kinetic models as well as diffusion kinetic models. It is found that no single kinetic model can fully describe the sorption process at all times. At least three independent rate-controlling mechanisms appear to compete each other and dominate the different stages of sorption.


Assuntos
Corantes/química , Purificação da Água/métodos , Adsorção , Corantes/isolamento & purificação , Difusão , Concentração de Íons de Hidrogênio , Cinética
18.
Water Res ; 37(16): 4018-26, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12909122

RESUMO

A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes. For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor. This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations. The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents. Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (<100 mbar). The process was applied in lab-scale to treat wastewater from the electronics industry. All toxic metals in question, namely copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits.


Assuntos
Conservação dos Recursos Naturais , Metais Pesados/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Eletrônica , Filtração , Resíduos Industriais , Íons , Membranas Artificiais
19.
J Pharm Biomed Anal ; 23(2-3): 421-8, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10933535

RESUMO

A high performance liquid chromatography (HPLC) method for the assay of fentanyl citrate, alfentanil hydrochloride, and sufentanil citrate swab samples was developed and validated in order to control a cleaning procedure. The swabbing procedure involved Super POLX 1200 wipers moistened with water. The assay employed extraction of swabs with water and analysis by isocratic, reversed-phase, HPLC with varying ultraviolet (UV) detection for desired sensitivity, depending on the analyte. The method was shown to be selective and linear from the limits of quantitation (0.10, 0.20, and 0.15 microg/swab for fentanyl citrate, alfentanil, and sufentanil, respectively) to over three times these concentrations. The assay limits (detection levels) per swab area were set at least at 0.2% of the concentrations of the actives in the drug products (0.02, 0.10, and 0.10 microg/swab or approximately 0.03, 0.02, and 0.2% for fentanyl citrate, alfentanil, and sufentanil, respectively). It should be noted that all active concentrations listed in this work were calculated based on the salt form concentration for fentanyl (citrate salt) and the free base forms for alfentanil and sufentanil. No reference standard was available for alfentanil hydrochloride and sufentanil citrate. Drug product was used instead throughout this study.


Assuntos
Alfentanil/análise , Analgésicos Opioides/análise , Cromatografia Líquida de Alta Pressão/métodos , Fentanila/análise , Sufentanil/análise , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta
20.
J Pharm Biomed Anal ; 19(5): 793-802, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10698543

RESUMO

A reversed phase high performance liquid chromatographic (HPLC) method was developed and validated for use as a stability indicating assay (potency and related substances) of paroxetine in paroxetine hydrochloride 20 mg tablets. Assay samples were extracted at a paroxetine concentration of 0.4 mg ml(-1) utilizing mobile phase as the extraction solvent. The chromatographic conditions employed a C18 column (Inertsil, 5 microm, 15 cm x 4.6 mm), isocratic elution with 10 mM 1-decane sulfonic acid sodium salt containing 10 mM sodium phosphate monobasic (pH 3.0)-ACN (60:40, v/v) and ultraviolet (UV) detection at 235 nm.


Assuntos
Paroxetina/análise , Inibidores Seletivos de Recaptação de Serotonina/análise , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Filtração , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Reprodutibilidade dos Testes , Soluções , Comprimidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA