Backstepping-based adaptive control of a quadrotor UAV with guaranteed tracking performance.

In this paper, a backstepping based indirect adaptive control design and an alternative direct adaptive control scheme, both with guaranteed transient and steady-state tracking performances, are proposed for trajectory tracking of a quadrotor unmanned aerial vehicle (UAV). Backstepping techniques, combined with a prescribed performance function based error transformation, are employed in both designs to achieve the bounded transient and steady-state tracking errors of the strict-feedback position system which comprises both lateral position and altitude dynamics. The effects of parametric inertia and drag uncertainties on attitude regulation are compensated using a least squares based parameter identification algorithm in the indirect adaptive control design, and using a constructive Lyapunov analysis approach in the direct adaptive control scheme. The stability of the closed-loop system for both designs is proven via Lyapunov analysis. Simulation and experimental test results are provided to verify the effectiveness of the proposed control designs.

Pneumoconiosis in dental technicians: HRCT and pulmonary function findings.

BACKGROUND: Pneumoconiosis is a form of diffuse interstitial lung disease, often resulting from occupational exposures. As dental prosthetic technicians (DPTs) build prostheses, they are exposed to many chemical materials that increase their risk of developing pneumoconiosis. AIMS: To document pulmonary function and prevalence of pneumoconiosis in DPTs. METHODS: A cross-sectional study of DPTs working in prosthetic laboratories who underwent pulmonary function test and high-resolution chest computed tomography (HRCT) scanning. RESULTS: There were 76 participants and pneumoconiosis was diagnosed in 46%. The most commonly seen radiological finding was round opacities, present in 38%. Agreement among HRCT readers was moderate to good. As defined by HRCT, emphysema was diagnosed more often in those with a longer occupational history or a history of smoking, and low carbon monoxide diffusion capacity (DLCO), but not in those with pneumoconiosis. Forced expiratory rate and DLCO were significantly lower in those who had worked 16 years or more (all P < 0.05). DLCO values were significantly lower in technicians with emphysema and in current smokers (all P < 0.01). Round opacities were also present in a substantial proportion of DPTs who had 15 years or less exposure. Because HRCT is able to detect radiological changes of occupational lung disease very early, the prevalence of pneumoconiosis in our participants was quite high. CONCLUSIONS: Pneumoconiosis identified by HRCT was present in almost half of DPTs surveyed. Appropriate education and workplace protection should be given to DPTs in order to prevent exposure to hazardous materials in dental prosthetics laboratories.

Salvage repair of anastomotic dehiscence following colon surgery using an expanded polytetrafluoroethylene graft.

Anastomotic dehiscence is a serious complication of colorectal surgery that causes death in up to 40% of cases in which it occurs. Edema and inflammation due to abdominal sepsis can prevent the use of standard management (i.e., colostomy, ileostomy or Hartmann's procedure), in which case alternative salvage repair methods are required. The present report describes the treatment of a 73-year-old female patient at high risk of mortality because of intraabdominal sepsis due to suture dehiscence following a right hemicolectomy and ileo-transversostomy. Several surgical repair procedures were tried, but all failed. We then used an expanded polytetrafluoroethylene (ePTFE) graft in salvage repair, and this approach proved successful. This is the first report to describe clinical, macroscopic and histopathological findings, following use of an ePTFE graft in colorectal repair in humans.

Serum mannose-binding lectin (MBL) gene polymorphism and low MBL levels are associated with neonatal sepsis and pneumonia.

OBJECTIVE: The aim of this study was to determine the serum mannose-binding lectin (MBL) levels and the frequency of MBL gene polymorphisms in infants with neonatal sepsis. STUDY DESIGN: Between January 2008 and January 2010, a total of 93 infants were included in this study and 53 of them had neonatal sepsis diagnosis as study group and 40 infants who had no sepsis according to clinical and laboratory findings as control group. RESULT: Serum MBL levels were found to be low in 17 of 93 infants. Eleven of them were in the sepsis group and six of them were in the control group. Serum MBL levels were significantly lower in infants with sepsis compared with the control group. Frequencies of genotype AB and BB were also significantly higher in the study group compared with the control group. Most importantly, presence of B allele of MBL exon 1 gene was found to be associated with an increased risk for neonatal sepsis. Additionally, in the study group, the mean serum MBL levels were found to be significantly lower in the premature infants compared with the term infants. Pneumonia, bronchopulmonary dysplasia (BPD) and intraventricular hemorrhage (IVH) were significantly higher in infants with MBL deficiency compared with infants with normal MBL levels. CONCLUSION: Low MBL levels and presence of B allele of MBL exon 1 gene were found to be important risk factors for development of both neonatal sepsis and pneumonia, especially in premature infants. Low MBL levels and MBL gene polymorphisms might also be associated with inflammation-related neonatal morbidities such as BPD and IVH.

Neonatal outcomes of pregnancy complicated by idiopathic thrombocytopenic purpura.

OBJECTIVE: The aim of this study was to determine the factors associated with the prognosis of newborns born to mothers with idiopathic thrombocytopenic purpura (ITP), and to compare the infants with/without thrombocytopenia in terms of maternal and neonatal characteristics. STUDY DESIGN: We reviewed the charts of 29 parturients with ITP and their newborns who were born between January 1998 and December 2008. RESULT: A total of 16 (55%) gravidas had been diagnosed with ITP before pregnancy and 13 (45%) were diagnosed during pregnancy. Thrombocytopenia was observed in 21 gravidas. In total, 17 (58%) gravidas received treatment to increase the platelet count. The majority of deliveries (72.5%) were vaginal. The infant platelet counts at birth ranged from 20 to 336 x 10(9) per liter. None of the neonates had complications attributable to the mode of delivery. Normal platelet counts were determined in 15 newborns, whereas 14 infants had thrombocytopenia at birth. Three (10.3%) neonates had mild, four neonates (13.7%) had moderate and seven neonates (24.1%) had severe thrombocytopenia. The age of the mothers having infants with thrombocytopenia was significantly higher (30+/-5.3 vs 25.3+/-3.8 years), most of the infants (10/14 (71%)) were males (P<0.05). CONCLUSION: Pregnancy complicated with ITP generally has a good outcome. Although ITP in pregnancy carries a low risk, careful observation is required for the newborn of gravidas with ITP even when the infant has no bleeding complications at delivery, and infants may require treatment for thrombocytopenia.

Management of isolated duodenal rupture due to blunt abdominal trauma: case series and literature review.

INTRODUCTION: Duodenal injuries are uncommon and are associated with significant morbidity and mortality due to delayed diagnosis (in the case of blunt trauma) or associated major vascular injuries (in the case of penetrating trauma). Isolated blunt injuries may have a subtle clinical presentation, and are particularly difficult to diagnose when the perforation is located in the retroperitoneal part of the duodenum. MATERIALS AND METHODS: This paper presents in company with three cases of successfully treated isolated duodenal injuries due to blunt trauma, focusing on with their preoperative diagnosis, surgical management and final out comes. CONCLUSIONS: Early diagnosis and successful surgical planning require experience and clinical suspicion on the part of the surgeon, as well as meticulous laparotomy results.

Comparison of serum amyloid A concentrations with those of C-reactive protein and procalcitonin in diagnosis and follow-up of neonatal sepsis in premature infants.

OBJECTIVE: The purpose of this study was to determine the role of serum amyloid A (SAA) in diagnosis of neonatal sepsis and evaluation of clinical response to antibiotic therapy. We also aimed to compare the efficiency of SAA with that of C-reactive protein (CRP) and procalcitonin (PCT) in diagnosis and follow-up of neonatal sepsis in preterm infants. STUDY DESIGN: A total of 163 infants were enrolled in this prospective study. The infants were classified into four groups: group 1 (high probable sepsis), group 2 (probable sepsis), group 3 (possible sepsis) and group 4 (no sepsis, control group). Blood samples for whole blood count, CRP, PCT, SAA and culture were obtained before initiating antibiotic treatment. This procedure was repeated three times at 48 h, 7 and 10 days. RESULT: Initial CRP, PCT and SAA levels were found to be positive in 73.2, 75.6 and 77.2% of all infants, respectively. Sensitivities of CRP, PCT and SAA at 0 h were 72.3, 74.8 and 76.4%, respectively. Although it was not statistically significant, SAA was found to be more sensitive than CRP and PCT in diagnosis of neonatal sepsis. The area under the curve (AUC) for CRP, PCT and SAA at 0 h were 0.870, 0.870 and 0.875, respectively. Although the AUC for SAA at 0 h was higher than PCT and CRP, the difference was not statistically significant. CONCLUSION: SAA is an accurate and reliable marker for diagnosis and follow-up of neonatal sepsis. It is especially useful at the onset of inflammation for rapid diagnosis of neonatal sepsis and can be safely and accurately used in combination with other sepsis markers such as CRP and PCT in diagnosis and follow-up of neonatal sepsis in preterm infants.

Reference values for neonatal thyroid volumes in a moderately iodine-deficient area.

BACKGROUND: The reference ranges of thyroid volumes in neonates vary according to the iodine status of a specific region. In different studies, it ranged between 0.47 and 1.62 ml. It has been previously shown that Bursa city was a moderately iodine-deficient area. We therefore aimed at determining normal reference ranges of neonatal thyroid volumes in our moderately iodine-deficient area. METHODS: In this cross-sectional study, thyroid volumes of 100 healthy fullterm neonates (51 boys and 49 girls; mean gestational age 38.9+/-1.1 weeks; and mean birth-weight 3370+/-446 g) were measured during the first week of life using thyroid ultrasonography. These data were compared with the gestational age, birth weight, gender, and TSH values of neonates as well as with maternal factors such as gestational diabetes, preeclampsia, smoking, medication use, and heart disease. RESULTS: All blood samples for TSH were taken during the first 5 days (mean 1.09+/-0.9 days). The mean TSH levels in all male and female neonates were 3.77+/-3.71, 4.57+/-3.61, and 2.93+/-3.66 mIU/l, respectively. This difference was statistically significant (p=0.006). Mean thyroid volumes for all male and female neonates were calculated as 0.82+/-0.18 (range 0.51-2.04), 0.84+/-0.21 (range 0.51-2.04), and 0.80+/-0.14 ml (range 0.58-1.30), respectively. There were no statistically significant differences in thyroid volumes with respect to gestational age, birth weight, gender, TSH values of neonates and maternal factors. CONCLUSION: Normal thyroid volumes in neonates vary between different regions. Local reference values should be used in thyroid volume assessment. Our results are in concordance with the literature and can be used as reference values for our region.

Difficulties in achieving optimal cytoreduction in primary peritoneal carcinoma management.

Primary peritoneal carcinoma (PPC) occurs mostly in older women and rarely in women under 50 years of age. The mean age of patients with PPC in our study was 65.5 years. We present the clinical and demographic data, management of cases and the results of six women who underwent exploratory laparotomy between January 2003 and August 2006.

Impact of fibrin sealant on Limberg flap technique: results of a randomized controlled trial.

BACKGROUND: Pilonidal disease is a common chronic disorder mainly seen in the sacrococcygeal region, especially in young males. Different surgical methods have been described for the treatment. Limberg flap has low morbidity and recurrence rates. Fibrin sealant, a two-component tissue adhesive composed of fibrinogen and thrombin, has been used in a number of surgical procedures to achieve hemostasis and to seal tissues. The purpose of this study was to investigate the impact of fibrin sealant on the Limberg flap procedure. METHODS: Between January 2003 and January 2004, 32 male patients with pilonidal disease were randomly assigned to receive the standard Limberg flap technique (n=16) alone or with fibrin sealant application (n=16) before drain insertion. RESULTS: The two groups were similar for age and body mass index. The total drainage volume was 64.4+/-28.0 ml in the control group and 16.2+/-13.6 ml in the fibrin sealant group (p<0.001). Moreover, hospitalization time was 3.9+/-0.6 days in the control group and 2.0+/-0 days in the fibrin sealant group (p<0.001). CONCLUSIONS: Use of fibrin sealant for Limberg flap technique shortens hospitalization time, reduces drainage volume and is therefore recommended.

Hardness and yield strength of dentin from simulated nano-indentation tests.

The finite element method (FEM) is applied for studying the hardness (H) and yield strength (Y) of dentin subjected to a nano-indentation process. The nano-indentation experiments were simulated with the ABAQUS finite element software package. This test, performed with a spherical indenter, was simulated by axisymmetric finite element analysis. The load versus displacement was calculated during loading-unloading sequence for different elastic modulus (E) and yield strength. Hardness and maximum principal compressive and tensile stresses were plotted for different elastic modulus depending on yield strength. The dentin was assumed to be isotropic, homogenous and elasto-plastic. The theoretical results outlined in this study were compared with the experimental works reported in the literature and then hardness and yield strength of dentin was estimated.

The role of omentoplasty in the surgical management of remnant cavity in hepatic hydatid cyst.

BACKGROUND: Cyst hydatid disease of the liver is still endemic in certain regions of the world. Currently, surgical operation remains the treatment of choice in hydatidosis. The cyst cavity can be managed by using capitonnage, external drainage, introflexion or omentoplasty. METHODS: Two hundred and thirty-five patients operated for hydatid cyst between January 1990 and February 2001 were analysed retrospectively. Either omentoplasty, external drainage, capitonnage or introflexion were used to treat residual cyst cavity. RESULTS: Patients were categorised into three groups to evaluate complications: omentoplasty alone (group A), omentoplasty combined with other techniques (group B) and other techniques (group C). The overall mortality rates were <1%. Overall morbidity rates were 8.8% for group A, 19% for group B and 25% for group C, respectively. Mean hospital stay was 7.6 days for group A, 11.9 days for group B and 15.8 days for group C. DISCUSSION: Postoperative surgical site infection, bile fistula, recurrence rate and overall morbidity were seen less frequently in patients who underwent omentoplasty in our series. Mean duration of hospital stay was significantly shorter in patients who underwent omentoplasty operations. Because omentum has a high absorptive capacity and the capability to fill the residual cavity, we recommend omentoplasty to manage patients with hydatid cyst of the liver, whether complicated or uncomplicated.

The progression of maternal RSV antibodies in the offspring.

The concentrations of maternal anti-RSV IgG antibodies were followed in 49 healthy newborns over the first six months of life. At birth, 41 mothers (83%) tested positive for anti-RSV IgG and all of their babies carried maternal anti-RSV IgG. Anti-RSV IgG positivity dropped to 73% at 1 month, 6% at 3 months, and 2% at 6 months. Between 3 and 6 months, 8% did acquire RSV infection, half of them as acute bronchiolitis and half as non-specific respiratory infection. All of the patients who acquired clinical RSV disease had an antibody concentration of <20 RU/ml which may be the cut off value for protection.

Effects of the sibutramine therapy on pulmonary artery pressure in obese patients.

AIM: Obesity is a major global public health problem. Previous drugs (dexfenfluramine and fenfluramine) used for the treatment of obesity have been withdrawn due to various cardiac side effects. Sibutramine is an anti-obesity agent. The purpose of this study was to assess cardiac valve disease and pulmonary artery pressure (PAP) of the patients who used once daily doses of sibutramine. METHODS: One hundred and six obese patients (51 men and 55 women) determined to have minimal tricuspid regurgitation (TR) on echocardiographic examination were included in the study. All patients had a complete physical examination, complete blood count and measurement of lipid parameters, and echocardiography was performed by which cardiac valves and PAP were evaluated. After the mean duration of 24-week of follow up, all examinations were repeated for each patient. RESULTS: The drug was well tolerated by all patients for the follow-up period. A significant weight loss was recorded in all patients compared to the baseline values (93.1 +/- 9.6 kg vs. 85.8 +/- 7.7 kg, p<0.001). Blood pressures and heart rate of the patients increased compared to the baseline measurements (systolic 122.3 +/- 8.5 vs. 124 +/- 10.2 mmHg, p=0.128, diastolic 79.3 +/- 4.7 vs. 80 +/- 5.7 mmHg, p=0.42 and heart rate 79.5 +/- 6.5 vs. 85 +/- 5.7 beats/min, p<0.001). Echocardiographically determined aortic or mitral valve dysfunction appeared in none of the patients. PAP lightly increased after the treatment but the difference between pre and post-treatment values was not found statistically significant (14.7 +/- 1.8 vs. 16.3 +/- 1.6 mmHg, p=0.06). CONCLUSIONS: A 24-week treatment with sibutramine does not affect heart valves and pulmonary artery pressure.

Idiopathic thrombocytopenic purpura in pregnancy: a single institutional experience with maternal and neonatal outcomes.

We observed 13 pregnant women of 70 females with idiopathic thrombocytopenic purpura (ITP) from January 1992 through September 2002. Thirteen mothers with ITP gave birth to twelve babies and two fetuses died. One of the pregnancies produced twins. Seven of the cases were diagnosed with ITP before pregnancy and six during pregnancy. One of the thirteen pregnancies was complicated by preeclampsia, one by ablatio placentae, and one by intrauterine death. Seven mothers received corticosteroid treatment, four high-dose immunoglobulin therapies, and one underwent splenectomy in the second trimester of gestation. At the time of delivery six mothers had normal platelet counts and seven had low platelet counts. Nine deliveries were by vaginal route and four were by cesarean section. Eleven infants were born with normal platelet counts and one was thrombocytopenic at the time of delivery. No infant showed any clinical signs of hemorrhage and there were no neonatal complications. Two fetuses died; one of them because of ablatio placentae and the other was intrauterine dead. In conclusion, ITP in pregnancy requires the management of two patients, the mother and her baby; hence, the close collaboration of a multidisciplinary group composed of a hematologist, obstetrician, anesthesiologist, and neonatologist is essential.

Management of intrabiliary ruptured hydatid disease of the liver.

BACKGROUND/AIMS: Intrabiliary rupture of hydatid cyst is an important complication of hydatid disease of the liver. The purpose of this study was to evaluate outcomes of patients with intrabiliary ruptured hydatid disease of the liver. METHODOLOGY: Two hundred and eleven patients were operated upon for hydatid cyst of the liver between 1990 and 1998 in our hospital. Twenty-four patients with intrabiliary rupture of hepatic hydatid cyst were retrospectively reviewed. RESULTS: Diagnosis of hydatid cyst was principally made using ultrasonography. We performed partial cystectomy + omentoplasty + transduodenal sphincteroplasty for 18 patients (75%). Daughter cysts and hydatid debris were found in common bile duct in 8 patients (33%). Internal opening of biliary fistula was found in 21 patients (87.5%). Morbidity rate was 12%. One patient died of unrelated causes. The average postoperative hospitalization period for the sphincteroplasty group was 7.6 days. CONCLUSIONS: Preoperative radiologic examination and laboratory values were not helpful to exclude an intrabiliary rupture of hydatid cysts in our patients. If bile stained cystic fluid is found, it is clear that a communication between hydatid cysts and the biliary tree exist. Transduodenal sphincteroplasty can be preferred in the management of intrabiliary ruptured hydatid disease because of short hospitalization, low morbidity, and ability to decompress intrabiliary pressure.

Meropenem in neonatal severe infections due to multiresistant gram-negative bacteria.

Recently, new broad spectrum carbapenem has been investigated on a world-wide scale for the treatment of moderate to severe infections. In the neonatal intensive care units the extensive use of third generation cephalosporins for therapy of neonatal sepsis may lead to rapid emergence of multiresistant gram-negative organisms. We report the use of meropenem in 35 infants with severe infections due to Acinetobacter baumanii and Klebsiella pneumoniae. All gram negative bacteria were resistant to ampicillin, amoxicillin, ticarcilin, cefazoline, cefotaxime, ceftazidime, ceftriaxone and aminoglycosides. Eighty two percent of the cases (29/35) were born prematurely. Assisted ventilation was needed in 85.7% (30/35). All infants deteriorated during their conventional treatment and were changed to meropenem monotherapy. Six percent (2/35) died. The incidence of drug-related adverse events (mostly a slight increase in liver enzymes) was 8.5%. No adverse effects such as diarrhea, vomiting, rash, glossitis, oral or diaper area moniliasis, thrombocytosis, thrombocytopenia, eosinophilia and seizures were observed. At the end of therapy, overall satisfactory clinical and bacterial response was obtained in 33/35 (94.3%) of the newborns treated with meropenem. Clinical and bacterial response rates for meropenem were 100% for sepsis and 87.5% for nosocomial pneumonia. This report suggests that meropenem may be a useful antimicrobial agent in neonatal infections caused by multiresistant gram negative bacilli. Further studies are needed to confirm these results: Meropenem, newborn, sepsis and nosocomial infection.