Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 41
Filter
1.
Environ Res ; 259: 119432, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38944104

ABSTRACT

The Mediterranean Basin has experienced substantial land use changes as traditional agriculture decreased and population migrated from rural to urban areas, which have resulted in a large forest cover increase. The combination of Landsat time series, providing spectral information, with lidar, offering three-dimensional insights, has emerged as a viable option for the large-scale cartography of forest structural attributes across large time spans. Here we develop and test a comprehensive framework to map forest above ground biomass, canopy cover and forest height in two regions spanning the most representative biomes in the peninsular Spain, Mediterranean (Madrid region) and temperate (Basque Country). As reference, we used lidar-based direct estimates of stand height and forest canopy cover. The reference biomass and volume were predicted from lidar metrics. Landsat time series predictors included annual temporal profiles of band reflectance and vegetation indices for the 1985-2023 period. Additional predictor variables including synthetic aperture radar, disturbance history, topography and forest type were also evaluated to optimize forest structural attributes retrieval. The estimates were independently validated at two temporal scales, i) the year of model calibration and ii) the year of the second lidar survey. The final models used as predictor variables only Landsat based metrics and topographic information, as the available SAR time-series were relatively short (1991-2011) and disturbance information did not decrease the estimation error. Model accuracies were higher in the Mediterranean forests when compared to the temperate forests (R2 = 0.6-0.8 vs. 0.4-0.5). Between the first (1985-1989) and the last (2020-2023) decades of the monitoring period the average forest cover increased from 21 ± 2% to 32 ± 1%, mean height increased from 6.6 ± 0.43 m to 7.9 ± 0.18 m and the mean biomass from 31.9 ± 3.6 t ha-1 to 50.4 ± 1 t ha-1 for the Mediterranean forests. In temperate forests, the average canopy cover increased from 55 ± 4% to 59 ± 3%, mean height increased from 15.8 ± 0.77 m to 17.3 ± 0.21m, while the growing stock volume increased from 137.8 ± 8.2 to 151.5 ± 3.8 m3 ha-1. Our results suggest that multispectral data can be successfully linked with lidar to provide continuous information on forest height, cover, and biomass trends.

3.
J Chromatogr A ; 1372C: 196-203, 2014 12 12.
Article in English | MEDLINE | ID: mdl-25468501

ABSTRACT

Monoclonal antibodies (mAbs) are promising reagents both for the manufacture of drug substances and for their employment as a drug themselves, but to be approved for utilization, according to FDA recommendations and WHO guidelines, they have to undergo verifications regarding their purity, stability and percentage of aggregates. Moreover, stability tests of lots have to be performed in order to verify molecular size distribution over time and lot-to-lot consistency. Recent works in literature have highlighted the need for suitable, sensitive and reliable complementary analytical techniques for the characterization of mAbs and quantification of aggregates. Size-exclusion chromatography (SEC) is the reference technique in the biopharmaceutical industry for its robustness, high performance and simple use; however it presents some limitations especially toward the separation and detection of aggregates with high molecular weight. On the other hand, flow field-flow fractionation (F4) in its miniaturized version (hollow fiber flow field-flow fractionation, HF5) shows comparable performances with interesting additional advantages: a broad size range, gentle separation mechanism with low dilution factor and higher sensitivity. To propose HF5 as a complementary technique for evaluating aggregates' content in mAbs samples, a comparative study of both SEC and HF5 performances has been made. In this work, SEC and HF5 were coupled with UV and multi-angle light scattering detection and employed first in separating standard samples of proteins mixture used as a sample model. Then, a screening of mobile phases and an evaluation of separation performances was performed on a therapeutic mAbs formulation, demonstrating the complementarities between SEC and HF5 and their possible use as a separative platform approach for the characterization and quality control of protein drugs.

4.
Anal Bioanal Chem ; 406(6): 1619-27, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24337135

ABSTRACT

The rapid development of protein-based pharmaceuticals highlights the need for robust analytical methods to ensure their quality and stability. Among proteins used in pharmaceutical applications, an important and ever increasing role is represented by monoclonal antibodies and large proteins, which are often modified to enhance their activity or stability when used as drugs. The bioactivity and the stability of those proteins are closely related to the maintenance of their complex structure, which however are influenced by many external factors that can cause degradation and/or aggregation. The presence of aggregates in these drugs could reduce their bioactivity and bioavailability, and induce immunogenicity. The choice of the proper analytical method for the analysis of aggregates is fundamental to understand their (size) dimensional range, their amount, and if they are present in the sample as generated by an aggregation or as an artifact due to the method itself. Size exclusion chromatography is one of the most important techniques for the quality control of pharmaceutical proteins; however, its application is limited to relatively low molar mass aggregates. Among the techniques for the size characterization of proteins, field-flow fractionation (FFF) represents a competitive choice because of its soft mechanism due to the absence of a stationary phase and application in a broader size range, from nanometer- to micrometer-sized analytes. In this paper, the microcolumn variant of FFF, the hollow-fiber flow FFF, was online coupled with multi-angle light scattering, and a method for the characterization of aggregates with high reproducibility and low limit of detection was demonstrated employing an avidin derivate as sample model.


Subject(s)
Fractionation, Field Flow/methods , Proteins/chemistry , Animals , Avidin/chemistry , Avidin/isolation & purification , Cattle , Lasers , Light , Limit of Detection , Particle Size , Protein Denaturation , Proteins/isolation & purification , Reproducibility of Results , Scattering, Radiation , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/isolation & purification
5.
Phys Rev Lett ; 110(18): 180601, 2013 May 03.
Article in English | MEDLINE | ID: mdl-23683183

ABSTRACT

We report an experimental and theoretical analysis of the energy exchanged between two conductors kept at different temperature and coupled by the electric thermal noise. Experimentally we determine, as functions of the temperature difference, the heat flux, the out-of-equilibrium variance, and a conservation law for the fluctuating entropy, which we justify theoretically. The system is ruled by the same equations as two Brownian particles kept at different temperatures and coupled by an elastic force. Our results set strong constraints on the energy exchanged between coupled nanosystems held at different temperatures.

6.
Rev Med Chir Soc Med Nat Iasi ; 116(1): 214-7, 2012.
Article in Romanian | MEDLINE | ID: mdl-23077898

ABSTRACT

UNLABELLED: The esophagogastric junction is a controversial anatomical area, due to its sphincteric mechanism which does not show an obvious anatomical basis. The aim of this study is to investigate the anatomical components that endoscopically indicate the mucosal esophagogastric junction in hiatal hernia patients. MATERIAL AND METHODS: The esophagogastric junction was investigated in 27 hiatal hernia patients undergoing surgery. Hiatal hernia is an extension of the stomach situated between the esophagogastric junction and the diaphragmatic indentation. The following types of hiatal hernia were found: sliding hiatal hernia (type I) in 4 patients (14.81%), rolling hiatal hernia (type II) in 2 (7.4%), mixed hiatal hernia (type III) in 12 (44.44%), type IV hiatal hernia in 4 (14.81%) and recurrent hiatal hernia in 5 (18.51%). Of the 27 hiatal hernia patients, 8 (29.6%) were operated using classical procedures: laparotomy--6 (75%) and laparoscopic surgery--2 (25%). RESULTS: The angle of His cannot be used for marking the mucosal esophagogastric junction due to the severe damage of the lower esophageal sphincter in hiatal hernia patients. The squamocolumnar junction is displaced in hiatal hernia patients and was not an option for the study group. The distal end of the esophageal longitudinal palisading vessels needs medication (proton pump inhibitors that reduce the gastric acid production), in order to enhance the visibility of these vessels. The proximal end of gastric longitudinal mucosal folds proved to be the most reliable site to identify endoscopically the mucosal esophagogastric junction. CONCLUSIONS: The anatomical structure of the esophagogastric junction differs in hiatal hernia patients and these peculiarities are very important in surgery.


Subject(s)
Esophageal Sphincter, Upper/anatomy & histology , Esophagogastric Junction/anatomy & histology , Hernia, Hiatal/pathology , Hernia, Hiatal/surgery , Laparoscopy , Endoscopy, Gastrointestinal/methods , Esophageal Sphincter, Lower/anatomy & histology , Hernia, Hiatal/classification , Humans , Stomach/anatomy & histology , Surgical Procedures, Operative , Treatment Outcome
7.
Chirurgia (Bucur) ; 107(2): 195-8, 2012.
Article in Romanian | MEDLINE | ID: mdl-22712348

ABSTRACT

The use of allografts in the surgical treatment of enenlarged hiatal hernias is a current hot topic of discussion. Using meshes in order to strengthen the hiatus of the esophagus is an efficient procedure which reduces the risk of reoccurences. In order to consolidate the initial surgical treatment of the enlarged hiatal hernias, polypropylene, polytetrafluoroethylene and biomaterial meshes are mainly used. There are ongoing discussions with regards to the use of meshes, their type and positioning. Although mesh usage is associated with a low recurrence rate, numerous authors have described complications such as: meshes migrating into the esophagus (caused by the alloplastic material used in the hiatoplasty), strictures, dysphagia, ulcers or perforations. From experience, the mesh used in the surgical treatment of hiatal hernia should preferably be non-biological and must be placed circumferentially, while fermly grounded at the pillar of the diaphragm. The correct placing of the mesh lowers the risk of strictures and degradation. Further prospective studies are needed in order to clarify the best method of surgically treating enlarged hiatal hernias.


Subject(s)
Hernia, Hiatal/surgery , Prostheses and Implants , Animals , Biocompatible Materials , Disease Models, Animal , Female , Polypropylenes , Polytetrafluoroethylene , Rabbits , Surgical Mesh , Transplantation, Homologous/methods , Treatment Outcome
8.
Ultramicroscopy ; 109(3): 264-7, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19110377

ABSTRACT

Nanoscale confinement of the magnetization in a magnetic element often results in the creation of a vortex structure. The vortex equilibrium state is characterized by the curling of the in-plane magnetization (chirality) and an out-of-plane core magnetization. The polarity of the vortex core can point up or down, independent of the chirality, and, thus, magnetic elements with a vortex core are interesting as four-state logic elements. We present an easy-to-use, quantitative method for the determination of both chirality and polarity from a single Fresnel image. This method offers direct evidence of the three-dimensional structure of a magnetic vortex and has significant advantages over the more complex methods currently in use.

9.
Phys Rev Lett ; 90(4): 043401, 2003 Jan 31.
Article in English | MEDLINE | ID: mdl-12570420

ABSTRACT

A systematic experimental study on muon-catalyzed fusion was conducted using a series of solid deuterium and tritium mixtures. A variety of conditions were investigated, i.e., tritium concentrations from 20% to 70%, and temperatures from 5 to 16 K. With decreasing temperature, we observed an unexpected decrease in the muon cycling rate (lambda(c)) and an increase in the muon loss probability (W). The origins of these observed changes were interpreted by the temperature-dependence in the dt mu formation process for lambda(c) and that in the muon reactivation process after muon-to-alpha sticking for W.

10.
Chirurgia (Bucur) ; 95(3): 285-9, 2000.
Article in Romanian | MEDLINE | ID: mdl-14768335

ABSTRACT

The authors present a study based on 4 cases of fistulous communication between the terminal digestive tube and the genitourinary tract, which appeared after surgery and radiation therapy for carcinoma of the uterine cervix. The diagnosis criteria (symptoms, clinical and imagistic findings), the objectives of the surgical treatment (external digestive derivation, treatment of the fistula and reconstruction of the digestive tube), the steps of the operation and the early and late postoperative evolution are pointed out. The conclusions are shown at the end.


Subject(s)
Radiation Injuries/complications , Rectovaginal Fistula/etiology , Vesicovaginal Fistula/etiology , Adult , Carcinoma/radiotherapy , Female , Humans , Middle Aged , Radiation Injuries/surgery , Rectovaginal Fistula/surgery , Retrospective Studies , Treatment Outcome , Uterine Cervical Neoplasms/radiotherapy , Vesicovaginal Fistula/surgery
11.
Chirurgia (Bucur) ; 95(1): 75-8, 2000.
Article in Romanian | MEDLINE | ID: mdl-14959646

ABSTRACT

The authors are presenting the case of a 53 year-old patient, suffering from type II diabetes mellitus and ankylosing spondylitis, admitted in our clinic in July 1997 for gastrojejunocolic fistula, 5 years after a transmesocolic gastrojejunostomy for obstructive chronic duodenal ulcer. The severe metabolic disorders and the radiologic aspects which led to the diagnosis, as well as the morphopathologic lesions found and the ways to approach the fistula, the stenotic duodenal ulcer and the reconstruction of the digestive continuity in a single surgical procedure are further discussed. The conclusions are shown at the end.


Subject(s)
Duodenal Ulcer/surgery , Gastroenterostomy/adverse effects , Intestinal Fistula/etiology , Humans , Intestinal Fistula/surgery , Male , Middle Aged , Reoperation , Treatment Outcome
12.
Int Dent J ; 47(4): 194-8, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9532459

ABSTRACT

The purpose of this survey was to assess the oral health situation of an industrial population in Romania. A total of 311 male and female employees (18-62 years-of-age) were clinically examined according to the WHO Basic Methods criteria and responded to an oral health questionnaire on dental knowledge and health care habits. In the younger age groups, the amount of untreated dental caries was high (18-24 years: DT = 5.7, DMFT = 8.9) whereas missing teeth were prominent in older employees (45 years or more: MT = 7.6, DMFT = 11.9). At age 25-44, 72 per cent had gingival bleeding and calculus. Dental knowledge was relatively poor, and 28 per cent of the participants indicated actual need for treatment. Dental visits within the previous 12 months were reported by 24 per cent of the employees, and 39 per cent had had a tooth extracted at their most recent visit. The study emphasises the need for reorientation of oral health care in Romania, and the relevance of industrial dental services for the implementation of oral health promotion and prevention is highlighted.


Subject(s)
Dental Caries/epidemiology , Occupational Health/statistics & numerical data , Tooth Loss/epidemiology , Adolescent , Adult , Analysis of Variance , Chi-Square Distribution , DMF Index , Dental Care/statistics & numerical data , Dentures/statistics & numerical data , Female , Health Behavior , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Oral Hygiene/statistics & numerical data , Periodontal Index , Romania/epidemiology
13.
Gan To Kagaku Ryoho ; 24(1): 43-7, 1997 Jan.
Article in Japanese | MEDLINE | ID: mdl-9020944

ABSTRACT

Combined chemotherapy of 5-FU and CDDP is useful for advanced or recurrent gastric cancer. To evaluate the efficacy of this chemotherapy, using human gastric carcinoma (NSC-30) maintained in the subcutaneous (sc) space in nude mice, we designed the following four experimental groups: 1) control group, 2) 5-FU group, 3) CDDP group, and 4) combined therapy group of 5-FU and CDDP (FP group). 5-FU (150 mg/kg) was injected into the intraperitoneal space for seven days using AlZet osmotic pumps. CDDP (9 mg/kg) was injected into the intraperitoneal space at one time. The tumor growth of drug administered groups was inhibited compared with the control group, especially in the FP group. Body weight and general condition of nude mice did not differ between groups. We also measured tumor concentrations of 5-FU and thymidylate synthetase (TS) total, free, inhibition rate between 5-FU group and FP group. The tumor 5-FU concentration of FP group was slightly higher than in 5-FU group, but the TS inhibition rate was almost the same. In conclusion, this combined therapy using Alzet osmotic pump is a useful drug sensitivity test as a conventional system.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Stomach Neoplasms/drug therapy , Animals , Cell Division/drug effects , Cisplatin/administration & dosage , Fluorouracil/administration & dosage , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Transplantation , Organ Size , Stomach Neoplasms/pathology
14.
Cancer ; 76(11): 2193-201, 1995 Dec 01.
Article in English | MEDLINE | ID: mdl-8635021

ABSTRACT

BACKGROUND: E-cadherin plays a crucial role in cell-cell adhesion in epithelial tissues. Recent studies have shown a correlation between decreased E-cadherin expression and cancer cell detachment. METHODS: The expression of E-cadherin was immunohistochemically analyzed using antihuman E-cadherin antibody in 121 cases of human gastric carcinoma. RESULTS: In noncancerous areas, the epithelial cells, including those with intestinal metaplasia, were stained positively in the plasma membrane. In contrast, E-cadherin expression of the cancer cells varied from case to case in primary and secondary sites. Tumors with a decrease in E-cadherin occurred significantly more frequently in undifferentiated adenocarcinoma (P < 0.05) and scirrhous type (P < 0.01). The rate of E-cadherin-negative tumors was higher in patients with peritoneal metastasis (P < 0.01) or in those with distant lymph node metastasis (P < 0.01), though the tumors with liver metastasis had relatively positive E-cadherin expression. Patterns of initial recurrence had similar results. Reduction or loss of E-cadherin expression correlated with shorter survival in patients after curative operation regardless of stage of disease. CONCLUSIONS: The decreased E-cadherin expression correlates with dedifferentiation, infiltrative tumor growth, distant metastasis, and poor survival for patients with gastric carcinoma. Thus, immunohistochemical study of E-cadherin may have clinicopathologic value for patients with gastric carcinoma.


Subject(s)
Cadherins/genetics , Carcinoma/pathology , Stomach Neoplasms/pathology , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Adenocarcinoma, Scirrhous/genetics , Adenocarcinoma, Scirrhous/pathology , Adult , Aged , Aged, 80 and over , Cadherins/analysis , Carcinoma/genetics , Carcinoma/secondary , Cell Adhesion/genetics , Cell Membrane/ultrastructure , Epithelium/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Liver Neoplasms/secondary , Lymphatic Metastasis/genetics , Lymphatic Metastasis/pathology , Male , Metaplasia , Middle Aged , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology , Peritoneal Neoplasms/genetics , Peritoneal Neoplasms/pathology , Peritoneal Neoplasms/secondary , Prognosis , Stomach Neoplasms/genetics , Survival Rate
15.
Cancer ; 76(9): 1529-36, 1995 Nov 01.
Article in English | MEDLINE | ID: mdl-8635053

ABSTRACT

BACKGROUND: Several studies have revealed a correlation between sialosyl Tn antigen (STN) and certain clinicopathologic features of various cancers, and that STN is an independent prognostic factor. However, the clinical significance of the expression of STN in gastric cancer has not been reported. Thus, the purpose of this study was to evaluate immunohistochemically the clinical significance of expression of STN in gastric cancer. METHODS: The expression of STN in surgically resected specimens of human gastric cancer was evaluated immunohistochemically using a monoclonal antibody (TKH-2), in 60 patients whose serum STN levels were measured and in 54 patients with advanced cancer who had been followed for more than 5 years after gastrectomy. The correlations between the level of STN expression and clinicopathologic factors were analyzed. The staining intensity was graded as follows: (-), less than 5% of the cancer cells expressed STN; (+), 5-50%; (++), more than 50%. RESULTS: Sialosyl TN antigen staining was detected mainly on the cell membrane, in the cytoplasm, and in the luminal contents, and 57.2% of the 60 specimens expressed STN, whereas the corresponding value for positive serum levels was 15%. A higher percentage of advanced tumors expressed STN than did the early cases, but the difference was not statistically significant. All cases with strong staining, the (++) cases, were advanced cases either with lymph node metastases or with cancer invading in or beyond the muscle layer proper. The expression of STN appeared to be related to the clinical stage, the extent of cancer invasion, and the presence of lymph node metastases. Sialosyl TN antigen was detected in the serum in less than 6% of the patients whose tumors were (-) or (+) for STN expression, and in 86.7% of the patients whose tumors expressed high levels of STN (++). The estimated 5-year survival in advanced cases (Stage III) was significantly better in those with negative STN expression than in those with positive STN expression (P < 0.01). CONCLUSIONS: These results suggest that STN may be a useful marker associated with the prognosis of patients with advanced gastric cancer.


Subject(s)
Antigens, Tumor-Associated, Carbohydrate/metabolism , Biomarkers, Tumor/metabolism , Stomach Neoplasms/immunology , Antigens, Tumor-Associated, Carbohydrate/blood , Biomarkers, Tumor/blood , Cell Membrane/immunology , Cytoplasm/immunology , Humans , Immunohistochemistry , Lymphatic Metastasis , Neoplasm Invasiveness , Prognosis , Retrospective Studies , Stomach Neoplasms/mortality , Stomach Neoplasms/pathology , Survival Rate
17.
Anticancer Res ; 15(4): 1355-8, 1995.
Article in English | MEDLINE | ID: mdl-7544565

ABSTRACT

The effect of a combination of TNP-470 (AGM-1470, an anti-angiogenic agent) and hyperthermia on tumor growth was examined using human esophageal (ESO-2) and gastric (NSC-8) cancers transplantable to nude mice. TNP-470 alone at a dose of 30 mg/kg three times a week for 2 weeks was sufficient to obtain an antitumor effect. A combination of this dose of TNP-470 and 43 degrees C hyperthermia for 30 min inhibited tumor growth markedly in comparison with either treatment alone. It was considered that angiogenesis after hyperthermia was inhibited by TNP-470, and then regrowth of the tumor cells was potently suppressed by reduction of O2 pressure, pH and nutrient supply in the tumor tissue.


Subject(s)
Antibiotics, Antineoplastic/therapeutic use , Esophageal Neoplasms/therapy , Hyperthermia, Induced , Neovascularization, Pathologic/prevention & control , Sesquiterpenes/therapeutic use , Stomach Neoplasms/therapy , Animals , Combined Modality Therapy , Cyclohexanes , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Transplantation , O-(Chloroacetylcarbamoyl)fumagillol , Transplantation, Heterologous
SELECTION OF CITATIONS
SEARCH DETAIL
...