Clinical value of water exchange colonoscopy / 中华消化内镜杂志

Objective To compare sedated water exchange and conventional colonoscopy in the recovery time,rates of reaching ileocecal valve and adenoma detection.Methods A total of 200 newly diagnosed patients undergoing colonoscopy with routine bowel preparation and propofol intravenous anesthesia were randomly divided into 2 groups:water exchange group (WE) and conventional group,100 patients in each group.The operations were performed by two experienced physicians.The recovery time,rates of reaching ileocecal valve and adenoma detection of each group were analyzed and compared after operation.Results The recovery times of patients in water exchange and conventional groups were 8.08±0.58 min and 12.34±0.72 min,respectively (F =2 147.33,P＜ 0.05).Rates of reaching ileocecal valve were 100.00％(100/100,WE group) and 96.00％ (96/100,conventional group),respectively(x2 =4.17,P＜0.05).Adenoma detection rates of whole colon were 43.00％ (43/100,WE group) and 29.00％ (29/100,conventional group) (x2=4.25,P＜0.05),of which small adenomas (＜ 1.0 cm) accounted for 83.96％ (89/106,WE group) and 70.59％ (48/68,conventional group) (x2 =4.43,P ＜ 0.05),respectively.Adenoma detection rates of proximal colon were 28.00％ (28/100,WE group) and 20.00％ (20/100,conventional group) (x2 =1.75,P＞ 0.05),of which small adenomas (＜ 1.0 cm) accounted for 90.41％ (66/73,WE group) and 74.47％ (35/47,conventional group) (x2 =5.45,P ＜ 0.05),respectively.Conclusion Water exchange colonoscopy can not only shorten the recovery time of patients,but also increase rates of reaching ileocecal valve and adenoma detection.

The hyporheic zone and its functions: revision and research status in Neotropical regions / A zona hiporréica e as suas funções: revisão e estado da arte da pesquisa na região neotropical

AbstractThe hyporheic zone (HZ), as the connecting ecotone between surface- and groundwater, is functionally part of both fluvial and groundwater ecosystems. Its hydrological, chemical, biological and metabolic features are specific of this zone, not belonging truly neither to surface- nor to groundwater. Exchanges of water, nutrients, and organic matter occur in response to variations in discharge and bed topography and porosity. Dynamic gradients exist at all scales and vary temporally. Across all scales, the functional significance of the HZ relates to its activity and connection with the surface stream. The HZ is a relatively rich environment and almost all invertebrate groups have colonized this habitat. This fauna, so-called hyporheos, is composed of species typical from interstitial environment, and also of benthic epigean and phreatic species. The hyporheic microbiocenose consists in bacteria, archaea, protozoa and fungi. The HZ provides several ecosystem services, playing a pivotal role in mediating exchange processes, including both matter and energy, between surface and subterranean ecosystems, functioning as regulator of water flow, benthic invertebrates refuge and place of storage, source and transformation of organic matter. The hyporheic zone is one of the most threatened aquatic environments, being strongly influenced by human activities, and the least protected by legislation worldwide. Its maintenance and conservation is compelling in order to preserve the ecological interconnectivity among the three spatial dimensions of the aquatic environment. Although several researchers addressed the importance of the hyporheic zone early, and most contemporary stream ecosystem models explicitly include it, very little is known about the HZ of Neotropical regions. From a biological standpoint, hyporheos fauna in Neotropical regions are still largely underestimated. This review focuses on a brief presentation of the hyporheic zone and its functions and significance as an ecotone. We also highlighted the key aspects considering also the current status of research in Neotropical regions.

ResumoA zona hiporréica, como ecótono de ligação entre a superfície e as águas subterrâneas, é parte funcional seja dos ecossistemas fluviais seja das águas subterrâneas. As características hidrológicas, as características químicas, biológicas e metabólicas são específicas desta zona, não pertencendo verdadeiramente nem a superfície nem às águas subterrâneas. Trocas de água, nutrientes e matéria orgânica ocorrem em resposta a variações na descarga, topografia do álveo e porosidade. Gradientes dinâmicos existem em todas as escalas e variam temporalmente. Em todas as escalas, o significado funcional da zona hyporheic relaciona-se com a sua conexão e atividades com a água superficial. O HZ é um ambiente relativamente rico e quase todos os grupos de invertebrados colonizaram este habitat. Esta fauna, chamada hyporheos, é composta por espécies típicas do ambiente intersticial, e também de espécies bentônicas epígeas e freáticas. A microbiocenose consiste em bactérias, arqueobactérias, fungos e protozoários. O HZ fornece vários serviços para o ecossistema, desempenhando um papel fundamental na mediação de processos de troca, incluindo seja a matéria, seja a energia, entre os ecossistemas superfíciais e os subterrâneos, funcionando como regulador do fluxo de água, de refúgio para invertebrados bentônicos e local de armazenagem, fonte e transformação de matéria orgânica. A zona hyporheic é um dos ambientes aquáticos mais ameaçados, sendo fortemente influenciado pelas atividades humanas, e um dos menos protegidos pela legislação em todo o mundo. A sua manutenção e conservação é necessaria para preservar a interconectividade ecológica entre as três dimensões espaciais do ambiente aquático. Apesar de vários pesquisadores aborem a importância da zona hyporheic a tempo, e a maioria dos modelos de ecossistemas atualmente incluí-lo de forma explicita, muito pouco se sabe sobre o HZ das regiões neotropicais. Do ponto de vista biológico, a fauna hiporréica das regiões neotropicais é ainda largamente subestimada. Esta revisão visa apresentar de forma resumida a zona hiporréica, suas funções e importância como ecótono. Também visa destacar os aspectos principais considerando também o estado actual da investigação em regiões neotropicais.

A randomized controlled study of water exchange colonoscopy and air insufflation colonoscopy / 中华消化内镜杂志

Objective To investigate the clinical application prospect of water exchange colonoscopy.Methods A total of 300 outpatients who underwent unsedated colonoscopy were randomized to the WEC group (n =150)or the AIC group(n =150).The maximum pain score, insertion time, the cecal intubation rate and the polyp detection rate were reported by an assistant during the insertion phase and at the end of colonoscopy.Results The maximum abdominal pain scores were 1.77 ± 1.29 in the WEC group and 2.84 ± 1.55 in the AIC group with significant difference (P =0.000).The intubation time of WEC was longer than that of AIC (11.91 ± 3.58 VS 8.03 ± 3.19 ,P =0.000)with no significant difference.There was no significant difference in the cecal access rate between the two groups(97.3％ VS 94.0％ ,P =0.157).The polyp detection of WEC was higher than that of AIC (16.7％ VS 10.0％, P =0.089).In the post abdominal operation subject of colonoscopy procedure, WEC had higher rate of cecal intubation than AIC ,the maximum abdominal pain score were 2.25 ± 1.63 in the WEC group,lower than 3.48 ± 1.45 in the AIC group.Conclusion Water exchange colonoscopy can alleviate patients' abdominal pain symptoms, but with longer insertion time.There are no significant difference in the cecal access rate and the polyp detection rate between two groups.For difficult colonoscopy, water exchange colonoscopy is helpful to increase the rate of cecal intubation.

Effects of rainfall on water quality in six sequentially disposed fishponds with continuous water flow

An investigation was carried out during the rainy period in six semi-intensive production fish ponds in which water flowed from one pond to another without undergoing any treatment. Eight sampling sites were assigned at pond outlets during the rainy period (December-February). Lowest and highest physical and chemical parameters of water occurred in pond P1 (a site near the springs) and in pond P4 (a critical site that received allochthonous material from the other ponds and also from frog culture ponds), respectively. Pond sequential layout caused concentration of nutrients, chlorophyll-a and conductivity. Seasonal rains increased the water flow in the ponds and, consequently, silted more particles and other dissolved material from one fish pond to another. Silting increased limnological variables from P3 to P6. Although results suggest that during the period under analysis, rainfall affected positively the ponds' water quality and since the analyzed systems have been aligned in a sequential layout with constant water flow from fish ponds and parallel tanks without any previous treatment, care has to be taken so that an increase in rain-induced water flow does not have a contrary effect in the fish ponds investigated.

O estudo foi efetuado durante o período de chuva (dezembro-fevereiro) em seis viveiros de produção semi-intensiva de peixes, a fim de avaliar o efeito da chuva na qualidade da água de viveiros que apresentam fluxo contínuo de água, a qual é passada de um viveiro para outro sem tratamento prévio. Foram amostrados oito pontos de coleta nas saídas dos viveiros. O viveiro P1 (próximo à nascente) apresentou as menores concentrações físicas e químicas da água e as maiores no viveiro P4 (considerado um ponto crítico recebendo material alóctone proveniente de outros viveiros e do escoamento do setor de criação de rãs). A disposição seqüencial dos viveiros estudados promoveu aumento nas concentrações dos nutrientes, clorofila-a e condutividade. As chuvas características desta época do ano aumentaram o fluxo de água nos viveiros e conseqüentemente, carreando material particulado e dissolvido de um viveiro para outro e, promovendo um aumento das variáveis limnológicas em direção do P3 ao P6. Os resultados sugerem que a chuva no período de estudo afetou positivamente a qualidade da água dos viveiros estudados, porém, como os sistemas analisados estão dispostos em distribuição seqüencial e escoamento constante da água de viveiros e tanques paralelos sem tratamento prévio, cuidados devem ser averiguados para que o aumento do fluxo de água provocado pelas chuvas não tenha efeito adverso nos viveiros estudados.

Effects of rainfall on water quality in six sequentially disposed fishponds with continuous water flow

An investigation was carried out during the rainy period in six semi-intensive production fish ponds in which water flowed from one pond to another without undergoing any treatment. Eight sampling sites were assigned at pond outlets during the rainy period (December-February). Lowest and highest physical and chemical parameters of water occurred in pond P1 (a site near the springs) and in pond P4 (a critical site that received allochthonous material from the other ponds and also from frog culture ponds), respectively. Pond sequential layout caused concentration of nutrients, chlorophyll-a and conductivity. Seasonal rains increased the water flow in the ponds and, consequently, silted more particles and other dissolved material from one fish pond to another. Silting increased limnological variables from P3 to P6. Although results suggest that during the period under analysis, rainfall affected positively the ponds' water quality and since the analyzed systems have been aligned in a sequential layout with constant water flow from fish ponds and parallel tanks without any previous treatment, care has to be taken so that an increase in rain-induced water flow does not have a contrary effect in the fish ponds investigated.

O estudo foi efetuado durante o período de chuva (dezembro-fevereiro) em seis viveiros de produção semi-intensiva de peixes, a fim de avaliar o efeito da chuva na qualidade da água de viveiros que apresentam fluxo contínuo de água, a qual é passada de um viveiro para outro sem tratamento prévio. Foram amostrados oito pontos de coleta nas saídas dos viveiros. O viveiro P1 (próximo à nascente) apresentou as menores concentrações físicas e químicas da água e as maiores no viveiro P4 (considerado um ponto crítico recebendo material alóctone proveniente de outros viveiros e do escoamento do setor de criação de rãs). A disposição seqüencial dos viveiros estudados promoveu aumento nas concentrações dos nutrientes, clorofila-a e condutividade. As chuvas características desta época do ano aumentaram o fluxo de água nos viveiros e conseqüentemente, carreando material particulado e dissolvido de um viveiro para outro e, promovendo um aumento das variáveis limnológicas em direção do P3 ao P6. Os resultados sugerem que a chuva no período de estudo afetou positivamente a qualidade da água dos viveiros estudados, porém, como os sistemas analisados estão dispostos em distribuição seqüencial e escoamento constante da água de viveiros e tanques paralelos sem tratamento prévio, cuidados devem ser averiguados para que o aumento do fluxo de água provocado pelas chuvas não tenha efeito adverso nos viveiros estudados.

(17)O NMR Study On Water Exchange Rate of Paramagnetic Contrast Agents

PURPOSE: The water exchange rate between bulk water and bound water is an important parameter in deciding the efficiency of paramagnetic contrast agents. In this study, we evaluated the water exchange rates of various Gd-chelates using oxygen-17 NMR technique. MATERIAL AND MEHTODS: The samples (Gd-DTPA, Gd-DTPA-BMA, Gd-DOTA, Gd-EOB-DTPA) were prepared by mixing 5% (17)O-enriched water (Isotech, USA). The pH of the samples was adjusted to physiological value (pH=7.0) by buffer solution. The variable temperature (17)O-NMR measurements were performed using Bruker-600 (14.1 T, 81.3 MHz) spectrometer. Bruker VT-1000 temperature control units were used to stabilize the temperature. The (17)O spin-spin relaxation times (T2) were measured using Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence with 24 echo trains. The variable temperature T2 relaxation data were then fitted into Solomon-Bloembergen equations using least square fit algorithm to estimate the water exchange times. RESULTS: From the measured (17)O-NMR relaxation rates, the determined water exchange rates at 300K are : 0.42 microsecond for Gd-DTPA, 1.99 microsecond for Gd-DTPA-BMA, 0.27 microsecond for Gd-DOTA, and 0.11 microsecond for Gd-EOB-DTPA. The Gd-DTPA-BMA showed slowest exchange whereas Gd-EOB-DTPA had fastest water exchange rate. In addition, it was found that the water exchange rates of all samples had exponential temperature dependence with different decay constant. CONCLUSION: (17)O-NMR relaxation rate measurements, when combined with variable temperature technique, provide a solid tool for studying water exchange rate, which is very important in investigating the detailed mechanism of relaxation enhancement effect of the paramagnetic contrast agents.