Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
Add more filters










Publication year range
1.
J Nucl Med ; 65(4): 512-519, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38485276

ABSTRACT

Accurate staging of invasive lobular carcinoma (ILC), a subtype of breast cancer, is vital for effective clinical management. Although 18F-FDG PET/CT is a commonly used tool, its efficacy varies across different histologic subtypes. To mitigate this challenge, our investigation delves into the potential utility of 68Ga-fibroblast activation protein inhibitor (FAPI) PET/CT as an alternative for staging ILC, aiming to address a significant research gap using a more expansive patient cohort than the smaller samples commonly found in the existing literature. Methods: In this retrospective analysis, women diagnosed with primary ILC of the breast underwent both 18F-FDG PET/CT and 68Ga-FAPI PET/CT. Both modalities were compared across all lesion locations with the used reference standard. The interval between scans was 1 wk, without any intervening treatments. Lesions were categorized visually, and tracer activity was analyzed using SUVmax, tumor-to-background uptake ratio, and uptake ratios. Both modalities were compared across various parameters, and statistical analysis was performed using SPSS 22.0. A P value of less than 0.05 was chosen to determine statistical significance. Results: The study included 23 female ILC patients (mean age, 51 y) with hormone-positive, human epidermal growth factor receptor type 2-negative tumors. Most (65%) had the luminal A subtype. 68Ga-FAPI PET/CT outperformed 18F-FDG PET/CT, with higher tumoral activity and tumor-to-background uptake ratios (P < 0.001). Primary tumors showed significantly increased uptake with 68Ga-FAPI PET/CT (P < 0.001), detecting additional foci, including multicentric cancer. Axillary lymph node metastases were more frequent and had higher uptake values with 68Ga-FAPI PET/CT (P = 0.012). Moreover, 68Ga-FAPI PET/CT identified more lesions, including bone and liver metastases. Pathologic features did not significantly correlate with imaging modalities, but a positive correlation was observed between peritumoral lymphocyte ratio and 68Ga-FAPI PET/CT-to-18F-FDG PET/CT uptake ratios (P = 0.026). Conclusion: This study underscores 68Ga-FAPI PET/CT's superiority over 18F-FDG PET/CT for ILC. 68Ga-FAPI PET/CT excels in detecting primary breast masses, axillary lymph nodes, and distant metastases; can complement 18F-FDG PET/CT in ILC; and holds potential as an alternative imaging method in future studies.


Subject(s)
Breast Neoplasms , Quinolines , Female , Humans , Middle Aged , Positron Emission Tomography Computed Tomography , Fluorodeoxyglucose F18 , Gallium Radioisotopes , Retrospective Studies , Positron-Emission Tomography , Breast Neoplasms/diagnostic imaging
2.
Dig Dis Sci ; 69(3): 961-968, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38340259

ABSTRACT

BACKGROUND: External biliary fistula, where the residual cyst is associated with the biliary tree, is one of the most common complications after liver hydatid cyst surgery. Surgical procedures become a consideration for patients in whom the biliary fistula persists despite all endoscopic procedures. However, reoperation for biliary fistula after hydatid cyst surgery leads to additional complications and increases morbidity and mortality. AIM: This study aims to treat persistent biliary fistulas that develop after liver hydatid cyst surgery using a simple noninvasive technique. MATERIALS AND METHODS: External drainage surgery was performed on 295 patients with liver hydatid cysts. Endoscopic treatment methods were used in patients who developed biliary fistula after surgery. Despite all endoscopic treatment methods, 14 patients developed persistent biliary fistulas. These patients were subsequently treated using the drain clamping technique. FINDINGS: All persistent fistulas occluded in 11.86 days (with a range of 8-20 days). No complications were observed in the one-year follow-up visits. CONCLUSION: Drain clamping, a novel approach to the treatment of persistent biliary fistulas developed despite all available endoscopic methods, can be safely used. This technique resulted in a complete recovery in patients without the need for surgical procedures.


Subject(s)
Biliary Fistula , Echinococcosis, Hepatic , Humans , Biliary Fistula/etiology , Biliary Fistula/surgery , Cholangiopancreatography, Endoscopic Retrograde/methods , Constriction , Echinococcosis, Hepatic/surgery , Echinococcosis, Hepatic/complications , Drainage , Postoperative Complications/etiology , Postoperative Complications/surgery , Retrospective Studies
3.
J Cancer ; 14(13): 2399-2409, 2023.
Article in English | MEDLINE | ID: mdl-37670968

ABSTRACT

Objectives: MicroRNAs (miRNAs) have important function in cancer development and progression. This study aims to determine the expression levels of miR-639, miR-641, miR-1915-3p, and miR-3613-3p in tissues of colorectal cancer (CRC) patients and the role of these miRNAs in the CRC pathogenesis. Methods: Tumor and non-tumor tissues were collected from a total of 59 CRC patients. qRT-PCR was used to identify the expressions of miR-639, miR-641, miR-1915-3p and miR-3613-3p. Through bioinformatics analysis, the target genes of miRNAs were identified by using DIANA mirPath v.3. Signaling pathways were generated using KEGG pathway database. Biological pathway, cellular component analysis, and analysis of Protein-Protein Interactions (PPI) Networks were performed using FunRich and STRING database. Results: Our findings revealed that miR-639, miR-641 and miR-3613-3p were significantly downregulated, and miR-1915-3p was significantly upregulated in tumor tissues compared to non-tumor tissues (p˂0.05). Furthermore, MAPK signaling pathway was the most enriched KEGG pathway regulated by miR-639, miR-641, miR-1915-3p and miR-3613-p. According to the FunRich, it was demonstrated that the targeted genes by miRNAs related to the cellular component and biological pathways such as beta-catenin-TCF7L2, axin-APC-beta-catenin-GSK3B complexes, Arf6 signaling, Class I PI3K signaling, etc. And, by the PPI analysis, it was established that the target genes were clustered on CTNNB1 and KRAS. Conclusions: These outcomes imply that miR-639, miR-641 and miR-3613-3p have tumor suppressor roles, while miR-1915-3p has an oncogenic role in the pathogenesis of CRC. According to the results of the current study, dysregulated miR-639, miR-641, miR-1915-3p, and miR-3613-3p might contribute to the development of CRC.

4.
Ir J Med Sci ; 192(4): 1695-1702, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36399322

ABSTRACT

AIM: The aim of this study is to determine accurately the localization of the adenoma with the imaging methods in the patients, who are planned to be operated on with prediagnosis of parathyroid adenoma. METHOD: In our study, the files of the patients who were considered to have parathyroid adenoma and underwent operation between 2012 and 2020 with the methods such as Tc99m-MIBI SPECT/CT, 18F-fluorocholine PET/CT, and ultrasound, and biochemical examinations were examined retrospectively. RESULTS: In this study, 31 (18.2%) male and 139 (81.8%) female adult patients were included. The sensitivities of localization methods were 82.6% for ultrasound and 78.4% for scintigraphy. Adenoma was localised in the right place in 14 of 15 (93.3%) patients with the 18F-fluorocholine PET/CT method. A statistically significant correlation was found between the sensitivity of scintigraphy, the gland weights (p: 0.002), and phosphor values (p: 0.039). A statistically significant improvement was observed in the intact PTH value (p: 0.001) 15 min after the removal of adenoma. A statistically significant improvement was observed in the serum PTH value (p: 0.001), the serum phosphorus value (p: 0.001), and the serum calcium (p: 0.001) in the first 3 months after the operation. CONCLUSION: Determining localization accurately for the patients enables performing operations with minimally invasive surgery successfully in a shorter time. Also, fewer complications and faster recovery are seen in the patients. It was concluded that studying intraoperative intact PTH and using 18F-fluorocholine PET/CT method for localization give more accurate results for localization and allow having more successful operation outcomes.


Subject(s)
Adenoma , Hyperparathyroidism, Primary , Parathyroid Neoplasms , Adult , Humans , Male , Female , Technetium Tc 99m Sestamibi , Parathyroid Neoplasms/diagnostic imaging , Parathyroid Neoplasms/surgery , Parathyroid Neoplasms/complications , Positron Emission Tomography Computed Tomography/methods , Parathyroid Glands , Hyperparathyroidism, Primary/complications , Hyperparathyroidism, Primary/surgery , Retrospective Studies , Tomography, Emission-Computed, Single-Photon , Adenoma/diagnostic imaging , Adenoma/surgery , Adenoma/complications
5.
Mol Imaging Biol ; 24(5): 789-797, 2022 10.
Article in English | MEDLINE | ID: mdl-35411447

ABSTRACT

PURPOSE: In this study, we aimed to investigate the utilization of 68Ga-FAPI PET/CT in comparison to 18FDG PET/CT to evaluate the peritoneal involvement of the gastrointestinal malignancies alongside primary lesions and other metastatic foci. PROCEDURES: A total of 37 patients with various gastrointestinal malignancies with accompanying peritoneal involvement who underwent 68Ga-FAPI PET/CT and 18FDG PET/CT imaging between September 2020 and June 2021 were included in this retrospective study. SUVmax values of 68Ga-FAPI and 18FDG were compared according to lesion locations. Also, the lesion localization ability of both imaging was compared in patient basis. RESULTS: Of the 37 patients with peritoneal involvement (23 males and 14 females; median age, 62.8 ± 12.7 years), 35.1% (n = 13) had colorectal cancer, 37.8% (n = 14) gastric cancer, and 27.0% (n = 10) pancreaticobiliary cancer. While 45.9% of them were operated, the remaining did not have surgery. The mean time interval between two studies was 3.2 days (range: 2-6 days). The mean SUVmax value of peritoneal metastases (p < 0.001) was significantly higher with 68Ga-FAPI PET/CT compared to that with 18FDG PET/CT, as in primary lesions (p < 0.001), lymph node metastases (p = 0.006), liver metastases (p = 0.002), and bone metastases (p = 0.018). A total of 185 lesions was detected in the initial assessment with 18FDG PET/CT. Of the total lesions detected with 18FDG PET/CT, 5 of them were evaluated as benign lesions with 68Ga-FAPI PET/CT also in accordance with the reference standard. In addition to 180 lesions detected with 18FDG PET/CT, a total of 37 additional malignant lesions, 12 of which were peritoneal metastases, were detected with 68Ga-FAPI PET/CT. CONCLUSION: 68Ga-FAPI PET/CT was determined to be superior to 18FDG PET/CT in terms of detection of peritoneal involvement with high image quality as well as primary tumor and other metastatic foci. Consequently, 68Ga-FAPI PET/CT can be used as a complementary imaging modality especially for inconclusive 18FDG findings due to the lack of accuracy of 18FDG PET/CT in some of the metastatic regions, especially in the liver.


Subject(s)
Gastrointestinal Neoplasms , Peritoneal Neoplasms , Quinolines , Male , Female , Humans , Middle Aged , Aged , Positron Emission Tomography Computed Tomography/methods , Fluorodeoxyglucose F18 , Gallium Radioisotopes , Radiopharmaceuticals , Peritoneal Neoplasms/diagnostic imaging , Retrospective Studies , Gastrointestinal Neoplasms/diagnostic imaging
6.
Ann Nucl Med ; 35(12): 1321-1331, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34436740

ABSTRACT

PURPOSE: We compared the ability of 68Ga-FAPI PET//CT with 18FDG PET/CT imaging techniques to detect additional lesions in breast cancer patients that may affect further chemotherapy options. METHODS: A total of 48 patients with breast cancer underwent concurrent 68Ga-FAPI-04 and 18FDG PET/CT regardless of whether they had received chemotherapy or not in the last month before imaging. Both modalities were compared according to various parameters: clinical/pathological features, number of lesions detected, activity uptake (SUVmax), and the effect on the evaluation of response to treatment in the post-chemotherapy group. RESULTS: This retrospective study included 48 patients with breast cancer (mean age 53.3 ± 11.7 years; IDC 89.6%; ILC 10.4%). In the comparison of both modalities, no statistical significance was obtained in terms of the pathological characteristics of the patients. More lesions were demonstrated in all categorized regions in 68Ga-FAPI PET/CT imaging with higher uptake values compared to 18FDG PET/CT in this study. In the treatment response evaluation of the post-chemotherapy group, 12 cases (12/24) who were evaluated as PMR, CMR, or SD according to 18FDG PET/CT results were later accepted as PD due to newly detected lesions in complementary 68Ga-FAPI PET/CT imaging and treatment of patients was managed accordingly by clinicians. CONCLUSION: It was determined that 68Ga-FAPI PET/CT was superior to 18FDG PET/CT in terms of accuracy and it was thought that 68Ga-FAPI PET/CT could be utilized as an additional complementary imaging to 18FDG PET/CT. Moreover, 68Ga-FAPI PET/CT, with its significant theranostic potential, could become a key element in predicting the pathological response of breast cancer patients in further researches.


Subject(s)
Positron Emission Tomography Computed Tomography
7.
Acta Chir Belg ; 118(1): 64-67, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28679320

ABSTRACT

INTRODUCTION: Rupture of superior mesenteric artery aneurysm (SMAA) is a very rare and life-threatening condition, presenting with acute intraabdominal hemorrhage. CASE: The patient was hospitalized upon complaint of nonspecific severe abdominal pain. Diagnosis of SMAA was established by abdominal Doppler ultrasound that showed a pseudo-aneurysmal lesion with size of 76 × 47 mm at the superior mesenteric main branch. Endovascular stenting was not performed because of the wide neck in the segment of the jejunal branches from SMA and the risk of branch loss during treatment. On the second day of hospitalization, the patient developed an acute abdomen. At explorative laparotomy for intraabdominal bleeding, the root of superior mesenteric artery was immediately and temporarily clamped to provide bleeding control. Aneurysmal tissue was resected and affected part was repaired by Dacron prosthetic graft to maintain proximal and distal vascular continuum. Intestinal viability was preserved. The patient survived disease-free as verified by his 18-month postoperative physical examination. CONCLUSIONS: The patient presents a very rare case showing ability to perform emergent intestine-sparing vascular surgery in ruptured SMAA. Surgery or endovascular treatment options should not be delayed especially in pseudo-aneurysms. It is critical to include ruptured SMAA in differential diagnosis of intraabdominal bleeding.


Subject(s)
Aneurysm, False/surgery , Aneurysm, Ruptured/surgery , Blood Vessel Prosthesis Implantation/methods , Gastrointestinal Hemorrhage/surgery , Mesenteric Artery, Superior/surgery , Abdominal Pain/diagnosis , Abdominal Pain/etiology , Acute Disease , Adult , Aneurysm, False/diagnostic imaging , Aneurysm, Ruptured/diagnostic imaging , Computed Tomography Angiography/methods , Follow-Up Studies , Gastrointestinal Hemorrhage/diagnostic imaging , Gastrointestinal Hemorrhage/etiology , Humans , Male , Mesenteric Artery, Superior/diagnostic imaging , Mesenteric Artery, Superior/physiopathology , Rare Diseases , Risk Assessment , Tomography, X-Ray Computed/methods , Treatment Outcome , Vascular Surgical Procedures/methods
8.
Turk J Surg ; 33(3): 185-189, 2017.
Article in English | MEDLINE | ID: mdl-28944331

ABSTRACT

OBJECTIVE: Neutrophil-lymphocyte ratio still has a limited clinical use due to many non-cancer factors affecting neutrophils or lymphocytes in the present time. We aimed to evaluate the association between preoperative neutrophil-lymphocyte ratio and poor prognostic factors after curative elective colorectal surgery. MATERIAL AND METHODS: This clinical retrospective study was initiated with 95 patients, who had a curative surgical resection between 2003 and 2013. The patients were divided into two groups based on the preoperative neutrophil-lymphocyte ratio cut-off value above and below 3. The groups were compared for tumor localization, diameter, and staging; the histopathological perineural invasion; lymphovascular invasion; and overall survival. Univariate and multivariate Cox regression analyses were used to determine the role of neutrophil-lymphocyte ratio after stratification by several clinicopathological factors. RESULTS: The mean age of patients was 59.79±1.48 (range, 23-90) years, and median follow-up period was 20.77±14.85 months. There was no significant difference in perineural or lymphovascular invasion, tumor size, stage, age, sex, and tumor location between the groups [Group 1 ratio >3 (n=52) and Group 2 ratio ≤3(n=43)]. Hemoglobin (p=0.035) and albumin levels (p=0.004) were lower in the Group 1. When the stage increased, differences between the rectal cancer groups were found. Overall survival was significantly lower in the Group 1 (p=0.013). CONCLUSIONS: The study showed that a high neutrophil-lymphocyte ratio had an adverse effect on overall survival in colorectal cancer patients who had a curative surgery. However, we could not establish any association between neutrophil-lymphocyte ratio and the factors such lymphovascular invasion, perineural invasion, tumor size expect hemoglobin and serum albumin levels.

9.
Case Rep Surg ; 2015: 375124, 2015.
Article in English | MEDLINE | ID: mdl-26295000

ABSTRACT

Insulinoma is the most frequently seen functional pancreatic neuroendocrine tumor. The incidence of multifocal insulinoma is lower than 10%. Its treatment is direct or laparoscopic excision. The present case was examined with the findings of hypoglycemia and hypercalcemia, and as there was high insulin and C-peptide levels the initial diagnosis was insulinoma. The case was investigated in terms of MEN 1. During preoperative screening for localization, there was one focus in the head of the pancreas in the abdominal tomography and two foci in endoscopic ultrasonography. No other focus was detected through intraoperative visual or manual palpation. However, five foci were detected during operation by intraoperative ultrasonography. The relation of masses with the main pancreatic canal was evaluated and they were excised by enucleation method. There was no recurrence during the postoperative 18-month follow-up of the patient. As a result, during treatment for insulinoma, it should be kept in mind that there might be multifocal foci. In all insulinomas, the whole pancreas should be evaluated with intraoperative ultrasonography because none of the current preoperative diagnostic methods are as sensitive as manual palpation of pancreas and intraoperative ultrasonography. The intraoperative detection of synchronous five foci in pancreas is quite a rare condition.

10.
Asian Pac J Cancer Prev ; 16(4): 1651-5, 2015.
Article in English | MEDLINE | ID: mdl-25743847

ABSTRACT

UGT1A play important roles in the glucuronidation of a variety of endogenous and exogenous compounds. UGT1A isoforms are expressed tissue specifically. The aim of this study was to examine the relationship between UGT1A3 and UGT1A7 mRNA expression and pancreatic cancer. Paired healthy and tumor tissue samples of 43 patients with pancreatic cancer were included in this study. UGT1A3 and UGT1A7 mRNA expressions were analyzed by real time-PCR. In the result of study, UGT1A3 and UGT1A7 mRNA expressions were significantly higher in tumor tissue than normal tissue of pancreatic cancer patients (p<0.05). In addition, high mRNA expression of UGT1A3 and UGT1A7 was significantly associated with larger tumor size (p<0.05). The data suggested that UGT1A3 and UGT1A7 may play roles in the progression of pancreatic cancer. Consequently, UGT1A3 and UGT1A7 are potential prognostic indicators.


Subject(s)
Biomarkers, Tumor/genetics , Glucuronosyltransferase/genetics , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Case-Control Studies , Female , Follow-Up Studies , Humans , Male , Middle Aged , Neoplasm Staging , Prognosis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction
11.
Asian Pac J Cancer Prev ; 15(17): 7181-5, 2014.
Article in English | MEDLINE | ID: mdl-25227811

ABSTRACT

Cyclin D1 is an important positive regulator of the G1/S phase of the cell cycle. We investigated the association between the CCND1 G870A polymorphism and susceptibility to papillary thyroid cancer in Turkish people. This study covered 102 patients with papillary thyroid cancer and 174 healthy controls. CCND1 genotyping was determined by the PCR-RFLP method. We found that the A allele frequency was higher in the cases than in the controls (p=0.042). On stratification analysis, papillary thyroid cancer risk was significantly elevated in individuals older than 45 years with the A allele (OR=1.91, 95% CI, 1.09-3.35, p=0.024) and in females with the A allele (OR=1.73, 95% CI, 1.06-2.84, p=0.029), compared to the G allele. According to the subject age, there was an increased papillary thyroid cancer risk for the individuals older than 45 years with the AA genotype (OR=2.28, 95% CI, 1.02-5.13, p=0.046) compared to the AG+GG combined genotypes. In conclusion, it is suggested that the CCND1 G870A polymorphism may contribute to the susceptibility to papillary thyroid cancer, especially in those who were older subjects (45 ≤ years old) and female, in the Turkish population.


Subject(s)
Carcinoma/genetics , Cyclin D1/genetics , Thyroid Neoplasms/genetics , Adult , Age Factors , Asian People/genetics , Carcinoma, Papillary , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Male , Middle Aged , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Polymorphism, Single Nucleotide , Sex Factors , Thyroid Cancer, Papillary , Turkey
12.
Ulus Cerrahi Derg ; 29(2): 49-53, 2013.
Article in English | MEDLINE | ID: mdl-25931845

ABSTRACT

OBJECTIVE: This study aimed to evaluate the effects of experimentally induced intra-abdominal hypertension on renal functions, with the combination of biochemical and histopathological properties. MATERIAL AND METHODS: Thirty male Wistar albino rats were used in this experimental study. Rats were divided into four groups. Group 1 (control group, n=6) only received anesthesia. After the induction of anesthesia, a 20 G catheter was introduced intraperitoneally to Group 2 (sham group, n=8), Group 3 (n=8) and Group 4 (n=8). The intra-abdominal pressure was not increased in Group 2. We applied 20 mmHg intra-peritoneal pressure to Group 3 and 30 mmHg to Group 4 for 3 hours. After withdrawing 3 mL intracardiac blood from all groups, the kidneys were removed for histopathological examination. Serum urea and creatinine levels were measured in all groups. RESULTS: Biochemical examination showed that blood urea and creatinine levels were statistically different among all groups (p<0.05). Serum creatinine levels in Group 3 and serum urea and creatinine levels in Group 4 were significantly increased. In the histopathological examination, the kidneys in Group 1 and Group 2 were classified as normal. In Group 3, areas with congestion were detected in the glomeruli and interstitial regions. In addition to these findings seen in Group 3, dilatation of the pelvi-caliceal structures and proximal ureters were noticed in Group 4. CONCLUSION: The levels of serum urea and creatinine are elevated when intra-abdominal pressure is increased due to kidney damage. Foci of hemorrhage in the interstitial area, dilatations in the proximal ureter, renal pelvis, and lymphatics were the pathologic findings seen in the kidneys under such circumstances.

13.
Molecules ; 13(5): 1135-1147, 2008 May 13.
Article in English | MEDLINE | ID: mdl-18560333

ABSTRACT

The difficult cultivation of the saffron plant (Crocus Sativus L.) make the spice of the same name made from its dried stigmas very valuable. It is estimated that some 75,000 blossoms or 225,000 hand-picked stigmas are required to make a single pound of saffron, which explains why it is the world's most expensive spice. The aim of this study was to identify ways of increasing the fertility and production of saffron. For this purpose, the treatment of saffron bulbs with a synthetic growth hormone--a mixture of Polystimulins A6 and K--and two different microorganism based materials--biohumus or vermicompost and Effective Microorganisms (EM)--in four different ways (hormone alone, biohumus alone, EM alone and EM+biohumus) was investigated to determine whether these treatments have any statistically meaningful effects on corms and stigmas. It has been shown that EM + biohumus was the most effective choice for improved saffron cultivation.


Subject(s)
Agriculture , Bacteria/metabolism , Crocus/drug effects , Crocus/growth & development , Plant Growth Regulators/pharmacology , Flowers/drug effects , Geography , Turkey
14.
Int J Mol Sci ; 9(4): 626-637, 2008 Apr.
Article in English | MEDLINE | ID: mdl-19325775

ABSTRACT

In this study, screw and nail withdrawal resistance of fir (Abies nordmanniana), oak (Quercus robur L.) black pine (Pinus nigra Arnold) and Stone pine (Pinus pinea L.) wood were determined and compared. The data represent the testing of withdrawal resistance of three types of screws as smart, serrated and conventional and common nails. The specimens were prepared according to TS 6094 standards. The dimensions of the specimens were 5x5x15cm and for all of the directions. Moreover, the specimens were conditioned at ambient room temperature and 65+/-2% relative humidity. The screws and nails were installed according to ASTM-D 1761 standards. Nail dimensions were 2.5mm diameter and 50 mm length, conventional screws were 4x50mm, serrated screws were 4x45mm and smart screws were 4x50mm. Results show that the maximum screw withdrawal resistance value was found in Stone pine for the serrated screw. There were no significant differences between Stone pine and oak regarding screw withdrawal resistance values. Conventional screw yielded the maximum screw withdrawal resistance value in oak, followed by Stone pine, black pine and fir. Oak wood showed the maximum screw withdrawal resistance value for the smart screw, followed by Stone pine, black pine, and fir. Oak wood showed higher nail withdrawal resistances than softwood species. It was also determined that oak shows the maximum nail withdrawal resistance in all types. The nail withdrawal resistances at the longitudinal direction are lower with respect to radial and tangential directions.

15.
Sensors (Basel) ; 8(9): 5745-5758, 2008 Sep 17.
Article in English | MEDLINE | ID: mdl-27873837

ABSTRACT

Value benefit analysis (VBA) is a psychometric instrument for finding the best compromise in forestry multiple-use planning, when the multiple objectives cannot be expressed in the same physical or monetary unit. It insures a systematic assessment of the consequences of proposed alternatives and thoroughly documents the decision process. The method leads to a ranking of alternatives based upon weighting of the objectives and evaluation of the contribution of each alternative to these objectives. The use of the method is illustrated with hypothetical data about Bolu-Lake Abant Natural Park (BLANP). In this study, in addition, computer software controlling the confidence was created. This software puts into practice the method proposed by Churchman and Ackoff, and determines the significance of the alternatives quickly and accurately.

SELECTION OF CITATIONS
SEARCH DETAIL
...