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Background and Objective: Previous cesarean sections are the most common cause of increased cesarean section in many parts of the world, although it is not always necessary. Considering the high statistics of cesarean section in Iran and especially the high rate of repeat cesarean section and creating motivation for vaginal birth after cesarean section, this study was conducted in order to investigate the maternal and neonatal outcomes of vaginal birth after one cesarean section. Methods: This cross-sectional study was conducted on 104 pregnant women with a previous caesarean section and transverse incision on the lower segment in Ayatollah Rouhani Hospital of Babol in two groups; 50 people in the first group who underwent repeat emergency cesarean section and 54 people in the second group who consented to vaginal birth after cesarean section (VBAC). Demographic characteristics and maternal and neonatal complications were investigated and compared between the two groups. Findings: In this study, there were no significant differences between the two groups in terms of demographic characteristics. Infant mortality rate was reported in 6 cases (12%) in the first group and 2 cases (3.7%) in the second group. Furthermore, 3 babies (6%) in the repeat cesarean section group and 9 babies (16.7%) in the vaginal birth group after cesarean section were admitted to the neonatal intensive care unit. The 5-minute Apgar was also significantly higher in the babies of the vaginal birth group after cesarean section (p=0.04). The duration of mother's hospitalization was 3.98±5.53 and 2.11±0.31 days in the repeat cesarean and vaginal birth groups, respectively (p=0.02). Conclusion: According to the results of this study, maternal and neonatal complications did not increase in vaginal birth after cesarean section, and if the mother wishes, vaginal birth can be performed after one cesarean section.

BACKGROUND AND OBJECTIVE: Preeclampsia is a common disease during pregnancy that may be associated with maternal and fetal mortality. Since the pathogenic process of preeclampsia begins during the first trimester of pregnancy, it is very difficult to identify biomarkers of early detection of preeclampsia. The aim of this study was to determine the predictive validity of systolic, diastolic and mean arterial blood pressure in the first trimester of pregnancy in the diagnosis of preeclampsia. METHODS: This case-control study was performed on 200 pregnant women referred to Ayatollah Rouhani Hospital in Babol within a historical cohort. The data of the records of 100 pregnant women with preeclampsia diagnosis (case group) and 100 healthy women (control group) were filled in special forms and compared. FINDINGS: According to ROC curve analysis, in the first trimester for systolic blood pressure at the cut-off point of 117.5, sensitivity of 56% and specificity of 70%, for diastolic blood pressure at the cut-off point of 72.5, sensitivity of 68% and specificity of 63% and for mean arterial pressure at the cut-off point of 87.5, sensitivity of 67% and specificity of 66% were calculated. Based on the area under the ROC curve, the diagnostic power was 0.706, 0.663 and 0.709, respectively (p

BACKGROUND AND OBJECTIVE: Ectopic pregnancy is a common complication and one of the causes of pregnancy-related deaths. Considering the increased prevalence of ectopic pregnancy in recent years and the increased risk factors such as assisted reproductive treatment, the present study was conducted to investigate the risk factors for ectopic pregnancy in Babol, northern Iran. METHODS: This case-control study was performed on pregnant women who were admitted with suspicion for ectopic pregnancy or acute abdomen within a 6-year period. Patients diagnosed with ectopic pregnancy were selected in the case group and the control group was selected from among the pregnant women's medical record during the same years. Patients were examined in terms of age, parity, history of abortion, type of contraception, history of ectopic pregnancy, history of pelvic infections, history of cesarean section, infertility treatment, history of smoking, marriages within the family, medical history and underlying disease. FINDINGS: In this study, 201 patients were examined in each group. The mean age for the case group was 29.75±5.6 and for the control group was 28.62±6.4 years. Among the risk factors, assisted reproductive treatment (OR=10.24, p≤0.001), abdominal and pelvic surgery (OR=2.35, p=0.002), infertility (p=6.76, p

BACKGROUND AND OBJECTIVE: Uterine rupture in all layers is not only a serious complication of pregnancy but is also associated with maternal and fetal mortality. The usual treatment for uterine rupture is termination of pregnancy, and hysterectomy is necessary in most cases. Successful repair of uterine rupture in all layers is not only uncommon but successful subsequent pregnancy is quite rare. A successful pregnancy is reported in a woman with a history of complete uterine rupture due to intramural pregnancy. CASE REPORT: A 28 – year – old pregnant woman, gravida 4, with a history of two abortions, and one delivery (stillbirth) was admitted to the high-risk pregnancy unit of Ayatollah Rouhani Hospital (Babol, Iran). She had a history of rupture of all layers of the uterus following intramural pregnancy in her third pregnancy, and at that time, she had undergone laparotomy and repair of the uterus. In the fourth pregnancy, due to the history of uterine rupture, she was under prenatal care in high-risk pregnancy unit, and after the onset of contractions at 36 weeks and 2 days, emergency cesarean section was performed for the patient, and the neonate was born with 10/10 APGAR score and a weight of 3000 grams. CONCLUSION: In women who become pregnant after a history of rupture of all layers of the uterus and after the repair of uterine, prenatal and fetal care should be done carefully and cesarean section should be performed immediately after the onset of labor contractions.

BACKGROUND AND OBJECTIVE: Ovarian cancer is the sixth common cancer among women in the world. Preoperative blood cell count can be a biomarker that predicts the severity of different types of cancer and determine the type of surgery. Therefore, the present study was conducted to determine the predictive role of the three blood markers of anemia, leukocytosis and thrombocytosis in the stage and grade of epithelial ovarian cancer before the operation. METHODS: In this cross-sectional study, the data of 60 patients with epithelial ovarian cancer were evaluated. Demographic data, hemoglobin, white blood cell count and platelets were statistically compared based on the stage of disease and the grade of mass differentiation as good, moderate and undifferentiated. FINDINGS: 61.1% of patients with thrombocytosis were in stage 3 and 33.3% of patients with leukocytosis were in stage 2 (p≤0.05), while 20.5% of the patients with anemia were in stage 3 (p>0.05). Moreover, 52.4% of patients with leukocytosis and 61.1% of patients with thrombocytosis had grade 3 tumor (p≤0.05), but only 34.1% of patients with anemia were in this group (p>0.05). Based on the evaluation of the ROC curve, cut-off point of the white blood cell was calculated to be 9050/ml with a sensitivity of 64% and specificity of 65% and platelet count was calculated to be 266000/ml with a sensitivity of 88% and specificity of 53%. CONCLUSION: Based on the results of this study, preoperative leukocytosis and thrombocytosis were correlated with stage and grade of epithelial ovarian cancer and had a predictive role.

BACKGROUND AND OBJECTIVE: Premature delivery is the presence of progressive uterine contractions before reaching 37 weeks of pregnancy. Since it is associated with perinatal complications and high costs, this study aimed to study the risk factors for premature delivery. METHODS: This cross-sectional study was conducted on 377 pregnant women with preterm labor (23-37 weeks) and 423 pregnant women of term delivery referring to Ayatollah Rohani Hospital of Babol city, Iran. We extracted and investigated the subjects’ demographic data, history of infertility, smoking habits, use of drugs, fast food consumption, history or presence of maternal illnesses and surgery, Urinary Tract Infections (UTI), Oligohydramnios, intrauterine growth restriction (IUGR), embryonic anomalies, premature rupture of membranes, vaginal bleeding as well as the neonatal data. FINDINGS: As observed in the two groups of preterm and term delivery respectively, there was employment during pregnancy in 83 (22%) and 51 (12%) cases, a history of preterm labor in 41 (10.9%) versus 21 (5%) cases, bleeding during the first trimester in 118 (31.3%) versus 61 (14.4%) cases, fast food consumption in 34 (9%) versus 14 (3.3%) cases, UTI in 150 (39.8%) versus 111 (26.2%) cases, anemia in 62 (16.4%) versus 29 (6.9%) cases, hypertension in 72 (19.1%) versus 13 (3.1%) cases and finally, smoking habits in 22 (5.8%) versus 5 (1.2%) subjects. There was a statistically significant association between the aforementioned variables (p

BACKGROUND AND OBJECTIVE: Pre-eclampsia is one of the most important complications in pregnancy. Early detection of pre-eclampsia in prenatal care is important. The aim of this study was to evaluate the value of increased levels of hemoglobin and hematocrit in first and second trimesters of pregnancy in predicting pre-eclampsia.METHODS: This case-control study was conducted on 140 pregnant women referred for delivery to Ayatollah Roohani hospital of Babol, Iran. Women with no signs of chronic hypertension, diabetes, kidney disease, smoking and using drugs that affect blood parameters were chosen. Data about pregnant hospitalized women, 70 ones diagnosed with pre-eclampsia (case group) and 70 ones from healthy pregnant women (control group) was filled in special forms and compared. FINDINGS: The mean age of patients was 27.21±5.7. The mean and standard deviation of hemoglobin in first trimester in case and control groups was 12.82±1.10 and 12.30±1.39, respectively (p=0.016). The mean and standard deviation of hemoglobin in second trimester in case and control groups was 11.90±1.39 and 11.46±1.37 respectively (p=0.011). CONCLUSION: This study showed that the level of hemoglobin and hematocrit in first and second trimesters of pregnancy is associated with preeclampsia.

BACKGROUND AND OBJECTIVE: Emergency peripartum hysterectomy (EPH) is a major surgery that usually performs in severe and life threatening bleeding after vaginal or cesarean delivery. Since, maternal morbidity and mortality is important in health system of our country so we studied incidence, indications, risk factors and complications of this surgery in pregnant women undergoing emergency peripartum hysterectomy at the hospitals of Babol University of medical sciences during 10 years.METHODS: This cross-sectional study was performed on pregnant women undergoing emergency peripartum hysterectomy in Shahid Yahyanejad and Ayatollah Roohani hospitals of Babol, Iran during 2002-2011. Data such as demographic data, type of delivery and hysterectomy, amount of blood transfusion, days of hospitalization, maternal and neonatal morbidity and mortality were gathered and the results were analyzed.FINDINGS: Twenty two EPH cases were identified among 37595 deliveries giving an incidence of 0.5 per 1000 deliveries that its rate in cesarean section delivery was 0.7 per 1000 and in vaginal delivery was 0.2 per 1000. The most indications of peripartum hysterectomy were 8 cases with uterine atony (36.4%) and 6 cases with abnormal placentation (27.3%), and the cesarean section and curettage were major risk factors for abnormal placentation. Blood transfusion was performed in all of patients and intra and postoperative complications included: 11 cases (84.6%) with intensive care admission that 5 cases (38.5%) of them had febrile morbidity and also 2 cases (15.2%) of them had vesical and urethral injury. There was 3 (13.6%) maternal death due to hemorrhagic shock. CONCLUSION: According to the results of this study, incidence of EPH in our study was more in cesarean section than vaginal delivery and history of previous cesarean section and curettage were the risk factors for abnormal placentation.

ABSTRACTBACKGROUND AND OBJECTIVE: With increasing life expectancy in women, they spend one third of their life after menopause. For this reason, the process of physical and psychosocial changes is very important in this stage of life. The aim of the present study was to assess the factors affecting life process of postmenopausal women.METHODS: This cross sectional study was performed on 700 postmenopausal women of Babol (Iran) aged between 40-60 years with natural menopause and without using hormone therapy by random and cluster sampling method. Data collection tool was a questionnaire consisting of two parts. First part assessed demographic factors and menopausal status of participants and second part was the questions related to life process by menopause specific quality of life (MENQOL) questionnaire in psychosocial and physical domains. After gathering information, the variables were assessed and compared. FINDINGS: The mean menopause age in Babol town was 48.57±1.55. The mean score of life quality in psychosocial and physical domains was 23.07±6.52 and 55.38±7.99, respectively. There was a significant relationship between psychosocial and physical dimensions of quality of life with age, education level and economic level (p

ABSTRACTBACKGROUND AND OBJECTIVE: Eighty percent of spontaneous abortion occurs in the first 12 weeks of pregnancy. Little information about the predictive value of ultrasound in predicting risks of spontaneous abortion is available. The aim of this study was to predict the risk of spontaneous abortion with the use of ultrasound markers.METHODS: This prospective study was performed on 239 pregnant women with regular menstrual cycles. For all patients at 6-8 weeks of gestation with vaginal sonography, gestational sac diameter, yolk sac diameter, and crown Rump length was measured and embryonic heart rate (HER) was recorded with Color Doppler sonography. Then the patients were followed between 3-4 weeks to the end of 20 weeks of pregnancy. FINDINGS: Of 239 pregnant women, who were studied, the pregnancy is continued in 221 (92.5%) patients after 20 weeks of pregnancy and 18 (7.5%) pregnancies have been resulted in abortion before 20 weeks of pregnancy. Using Pearson correlation between gestational age and EHR in the ones who their pregnancies were without abortion showed that there was a significant relationship (r=0.31, p

BACKGROUND AND OBJECTIVE: There are different methods of labor induction in PROM at term pregnancy including oxytocin and some prostaglandin such as misoprostol. Misoprostol has different effects on the induction of labor in PROM with different methods and dosages. The aim of this study was to compare the efficacy of oral misoprostol with oxytocin and oxytocin alone in induction of labor at term pregnant women with premature rupture of membranes.METHODS: This clinical trial study was performed on 99 term pregnant women with PROM who in the first 4 hours after PROM for delivery were admitted in Ayatollah Roohani and Shahid Beheshti hospitals of Babol, Iran. They were randomly assigned in a double-blinded manner to two groups. Misoprostol 50µg in two doses was administered 4 and 8 hours after rupture of membranes to one group (49 patients) and placebo was administered up to two doses to the other group (50 patients). When labor did not occur after 12 hours of rupture of membrane, oxytocin was administered for induction of the labor in both groups. Then type of delivery, cause of cesarean, duration between PROM until delivery, appropriate uterine contraction and maternal complications such as chorioamnionitis and uterine hyperstimulation were recorded and compared.FINDINGS: Average duration between rupture of membranes and delivery was similar to each other in two groups (14.3±3.4 hours in misoprostol group in compare with 15.6±3.29 hours in placebo group) (p=0.061). Average duration between rupture of membranes and uterine contraction was significantly shorter in misoprostol group (8.06±3.8 hours in compare with 9.8±3.9 hours) (p=0.027). The rate of vaginal delivery in misoprostol group was 30 (61.2%) and in placebo group was 24 (48%), and the rate of cesarean delivery in misoprostol group was 19 (38.8%) and in placebo group was 26 (52%), that there was not a significant difference (p=0.13). Maternal complications were not different in two groups.CONCLUSION: Results of this study showed that oral misoprostol 50µg in comparison with placebo could start uterine contraction without the increase of maternal and neonatal complications.

BACKGROUND AND OBJECTIVE: HELLP syndrome is a serious presentation of pre-eclampsia and eclampsia during pregnancy and its diagnosis is difficult because of lack of specific features. This syndrome is associated with prenatal and neonatal morbidity and mortality. The aim of the present study was to compare the maternal and neonatal outcomes of HELLP syndrome with preeclampsia in Yahyanejad hospital (Babol, Iran) in the past ten years.METHODS: This cross-sectional study was performed on all patients with pre-eclampcia/eclampcia who were hospitalized in Yahyanejad hospital during 10 years. Primary data, clinical and laboratory data, prenatal and maternal complications included (cesarean section, placental abruption, need to blood transfusion, liver hematoma, pulmonary edema, acute renal failure, DIC, brain hematoma and infection, intra-abdominal hemorrhage, ARDS and maternal mortality) and neonatal complications included (preterm neonates, IUGR, NICU admission and neonate mortality) were compared.FINDINGS: In this study, from 445 patients who were evaluated, 361 patients (81.3%) with mild preeclampsia, 83 patients (18.7%) with severe pre eclampsia and 1 (%0.2) with eclampsia were hospitalized in primary diagnosis, that 12 patients (2.7%) had HELLP syndrome symptoms. Cases of placental abruption, liver hematoma, pulmonary edema, need to blood transfusion, acute renal failure, DIC and maternal mortality in patients with HELLP syndrome was significant in compared to preeclampsia (p

BACKGROUND AND OBJECTIVE: Preeclampsia is one of the most prevalent diseases in pregnancy that include proteinuria and hypertension and can be associated with morbidity and mortality in mother and neonate. Endothelial cell dysfunction and inflammation are considered to have a crucial role in the pathophysiologic mechanism of preeclampsia. A systemic inflammatory response involves both the immune system and the clotting and fibrinolytic system. The aim of this study was to determine the association of fibrinogen and C-reactive protein (CRP) with the severity of preeclampsia. METHODS: This cross-sectional study was performed on 44 normal pregnant women, 35 cases with mild preeclampsia and 19 cases with severe preeclampsia that referred to Shahid Yahyanejad hospital, Babol, Iran. All of patients were primigravida and single pregnancy, cases over the age of 15 and gestational age of 30 to 40 weeks. Patients didn receive betamethasone in last week. The diagnosis of preeclampsia is made whose blood pressure reaches 140/90 mmHg or greater with proteinuria (trace or greater in random urine samples). Blood sample were taken from all subjects to measure CRP and fibrinogen and send to single laboratory. Then the groups were compared.FINDINGS: The mean of CRP was significantly different in control (2.28±0.81) and mild preeclampsia group (4.91±5.99) (p=0.03), and there was not significant difference between control (2.28±0.81) and severe preeclampsia group (3.8±3.05). The mean of fibrinogen was not significantly different in control group (360.5±62.35) and mild preeclampsia (344.71±65.07) and severe preeclampsia groups (340.95±78.62). CONCLUSION: Results show that CRP increased in mild preeclampsia in comparison with control group but there was not significant difference between fibrinogen level in control group with mild and severe preeclampsia.

BACKGROUND AND OBJECTIVE: Corticosteroids has been used for pregnant women for fetal lung maturation but there are many controversies about their effect and side effect, the aim of this study was to determine the effect of bethamethasone on the serum marker of infection in women at high risk for preterm delivery. METHODS: This prospective study was performed on 50 pregnant women at risk for preterm labor between 28-34 weeks of gestation who were treated by betamethasone (12 mg every 12 hours for 2 doses) for enhancement of fetal lung maturation in Shahid Yahyanejad hospital in Babol. Blood test for WBC, ESR and CRP were drawn before Bethamethasone injection, 2 hours after injection and second and third days after injection. The data were compared.FINDINGS: Mean gestational age was 31.9±2.4 weeks. The mean WBC (396±81) (p=0.000), neutrophil (473±109) (p=0.000) and ESR (1.8±0.6) (p=0.008) after treatment was significantly higher than before treatment. But mean of lymphocyte before and after treatment showed no significant difference. CRP value was increased significantly after treatment (p=0.009).CONCLUSION: The results of this study showed that antenatal betamethasone therapy causes a transient increase in maternal serum indicators of infection but returns to basic level soon.

BACKGROUND AND OBJECTIVE: Raloxifen is used widely to prevent menopause complications. Hyperlipidemia is a risk factor for coronary heart disease in menopausal women. There are controversies about raloxifen effects on serum lipids, so this study was done to determine the effects of raloxifen (ralofen) on serum lipids of the menopausal women.METHODS: This before-after interventional study was done on 50 menopausal women that returned to menopausal clinic of Yahyanejad hospital in Babol in 2008. Inclusion criteria were 45–60 years old and past of one year of last menstural period. Exclusion criteria were history of cancer, abnormal uterus bleeding, clotting dysfunction, use of androgen, corticosteroid and estrogen, renal failure, chronic and acute disease of liver, history of deep vein thrombosis and cardiovascular disease. Patient received ralofen (product by Aboryhan company) 60 mg/day for three months. Serum lipid level measured in three times include: before treatment, one month and three month later. FINDINGS: The mean age (±SD) of the patients was 53.2±3.7 and the median time of last menstural period was 6 years. The mean level of serum triglyceride (mg/dl) of menopausal women was significant (p=0.012) before treatment (159.6±36.1 mg/dl), one month after treatment (162.9±34.8 mg/dl) and three month after treatment (170.8±41.7 mg/dl). So the mean level of serum cholesterol (mg/dl) of menopausal women was significant (p=0.000) before treatment (193.6±22.2 mg/dl), one month after treatment (198.6±24.9 mg/dl) and three month after treatment (202.1±26.7 mg/dl).The mean level of serum LDL (mg/dl) of menopausal women was not significant (p=0.152) before treatment (114.6±28.3 mg/dl), one month after treatment (118.8±29.6 mg/dl) and three month after treatment (113.9±26.7 mg/dl). So the mean level of serum HDL (mg/dl) of menopausal women was not significant before treatment (47.8±9.3 mg/dl), one month after treatment (46.7±8.5 mg/dl) and three months after treatment (48.2±5.8 mg/dl). CONCLUSION: This study showed that ralofen had no significant effects on serum lipids levels and triglyceride and cholesterol increased were in normal and borderline limits that don have clinical importance.

BACKGROUND AND OBJECTIVE: Corticosteroids have been used for pregnant women for fetal lung maturation but there are many controversies about their effects and side-effects, the aim of this study was to determine the effects of betamethasone on the hemodynamic changes (heart rate and blood pressure) in pregnant women.METHODS: This clinical trial study performed on 100 pregnant women at risk of preterm delivery between 24-34 weeks of gestation in Yahyanejad hospital in Babol (2006). Betamethasone was injected 12 mg (2 doses with 12 hours interval, IM) and systolic blood pressure, diastolic blood pressure and heart rate were measured before injection (2 times with 5 minute interval) and after first and second dose injection (after each dose 2 times with 2 hours interval). The data were analyzed by SPSS soft ware and compared.FINDINGS: The mean age of our patients was 24.2 4.7 years (16–40 years). The mean gestational age of our patients was 32.4 2.6 weeks. The mean average of maternal heart rate after first dose of betamethasone administration (85.2 8.2) was significantly higher than before treatment (84 8.2) (p= 0.033). But there was no significantly difference between the mean average of maternal systolic and diastolic blood pressure before and after each dose administration. CONCLUSION: Our results show that betamethasone don have any significant effect on systolic and diastolic blood pressure changes in pregnant women but it may increase the mean of maternal heart rate after first dose of injection that this change is transient. Betamethasone has no significant effect on the hemodynamic changes in mother.

BACKGROUND AND OBJECTIVE: Pregnancy, neonatal and fetal complications are higher in twin than singleton pregnancy. Considering use of assisted reproductive technology (ART) and twin births is increased, the aim of this study was to compare the complications in spontaneous vs. assisted conception twin pregnancies for recognition of high risk mothers and prevention and treatment of them as soon as possible.METHODS: This analytical study was performed on 40 assisted conception twin pregnancies and 80 pregnant women with spontaneous twin pregnancies. Two groups were matched for age. Maternal morbidity (preeclampsia, preterm delivery) and neonatal complications (Intra uterine growth restriction and low birth weight) were recorded and compared.FINDINGS: Mean gestational age in spontaneous pregnancy was 34.4±3.2 weeks and in ART pregnancy was 33.7±2.1 weeks that showed no significant difference. Gestational diabetes was in 13 versus 8 cases (p=0.004), intrauterine growth restriction in 3 cases versus 0 (p=0.035) and transfer to neonatal intensive care unit 30 cases versus 26 (p=0.000) in ART pregnancy and spontaneous, respectively. Birth weight in ART pregnancy was significantly lower than spontaneous group (p=0.002, 0.004). Premature rupture of membrane, preeclampsia, placental events, intrauterine fetal death and gestational age had not significant difference between two groups. CONCLUSION: Because some of maternal and fetal morbidity in twin pregnancies was higher in assisted conceptions than spontaneous conception, these patients need closer prenatal care.

BACKGROUND AND OBJECTIVE: Abdominal pregnancy is a rare event but is associated with significant morbidity and mortality. The clinical presentation of abdominal pregnancy varies, and the diagnosis depends on a high index of suspicion. Clinical history, physical examination and ultrasonographic features are all non-specific.CASE: A 29-years-old woman, G1, presented with a history of 4 days of vaginal bleeding and treated as missed abortion. After medical treatment failure, we decided to do D;C (Dilation and Curettage) for termination of pregnancy. After evaluation of cervix under anesthesia, with suspicious of abnormal pregnancy, laparotomy was done. In laparotomy abdominal pregnancy was diagnosed. Fetus and placenta was removed from the cul-de-sac, and the patient remained well after the operation. CONCLUSION: There are many pitfalls in diagnosing abdominal pregnancy by examination and ultrasound. Laparoscopy or laparotomy is required to make a definitive diagnosis of abdominal pregnancy. For abdominal pregnancy, surgical interventions are recommended.

The emission spectra from an industrial, droplet-based, laser-produced plasma, extreme ultraviolet light source for nanolithography are here presented and analyzed. The dependence of spectral features on the CO2-drive-laser intensity is studied by changing the beam spot size at constant pulse energy and duration. We characterize the spectrum by fitting the results of atomic structure calculations to the short-wavelength region (7–11 nm), where the contributions from various charge states can be resolved, and obtain the relative contributions of charge states Sn9+ –Sn15+ . These relative contributions are compared to charge state populations as calculated with the non-equilibrium plasma kinetics code flychk. The calculations are shown to be in good qualitative agreement with the results, showing that the effective plasma temperature, and with it, the shape of the unresolved, main emission feature at 13.5 nm, is a remarkably weak function of laser intensity under this source normal operating conditions. [ABSTRACT FROM AUTHOR]

We present simultaneous 1D imaging and broadband spectroscopy of a laser-produced plasma (LPP) source of extreme ultraviolet light, using a tapered zone plate that is matched to the dispersion of a transmission grating. We describe the design and fabrication of the zone plates in the 5-80 nm wavelength regime with designed spatial resolution of ∼10 µm and spectral resolution of ∼0.8 nm. Subsequently, we benchmark the imaging spectrometer with a solid tin target LPP. Plane wave propagation simulations qualitatively match the experimental results and confirm the device performance.

In the present work the impact of in situ photoreduction, by means of ultraviolet (UV) irradiation, on the nonlinear optical response (NLO) of some graphene oxide (GO), fluorographene (GF), hydrogenated fluorographene (GFH) and graphene (G) dispersions is studied. In situ UV photoreduction allowed for the extended modification of the degree of functionalization (i.e., oxidization, fluorination and hydrogenation), leading to the effective tuning of the corresponding sp 2 /sp 3 hybridization ratios. The nonlinear optical properties of the studied samples prior to and after UV irradiation were determined by means of the Z-scan technique using visible (532 nm), 4 ns laser excitation, and were found to change significantly. More specifically, while GO's nonlinear optical response increases with irradiation time, GF and GFH present a monotonic decrease. The graphene dispersions' nonlinear optical response remains unaffected after prolonged UV irradiation for more than an hour. The present findings demonstrate that UV photoreduction can be an effective and simple strategy for tuning the nonlinear optical response of these graphene derivatives in a controllable way, resulting in derivatives with custom-made responses, thus more suitable for different photonic and optoelectronic applications.

An experimental study of laser-produced plasmas is performed by irradiating a planar tin target by laser pulses, of 4.8 ns duration, produced from a KTP-based 2-µm-wavelength master oscillator power amplifier. Comparative spectroscopic investigations are performed for plasmas driven by 1-µm- and 2-µm-wavelength pulsed lasers, over a wide range of laser intensities spanning 0.5 - 5 × 10 11  W/cm 2 . Similar extreme ultraviolet (EUV) spectra in the 5.5-25.5 nm wavelength range and underlying plasma ionicities are obtained when the intensity ratio is kept fixed at I 1µm /I 2µm = 2.4(7). Crucially, the conversion efficiency (CE) of 2-µm-laser energy into radiation within a 2% bandwidth centered at 13.5 nm relevant for industrial applications is found to be a factor of two larger, at a 60 degree observation angle, than in the case of the denser 1-µm-laser-driven plasma. Our findings regarding the scaling of the optimum laser intensity for efficient EUV generation and CE with drive laser wavelength are extended to other laser wavelengths using available literature data.

The nonlinear optical response of some O-doped polycyclic aromatic hydrocarbons (PAHs) is systematically investigated in the present work aiming to understand the influence of structural effects on their nonlinear optical response. In that view, the third-order nonlinear optical properties of these PAHs were measured under 4 ns visible (532 nm) and infrared (1064 nm) laser excitation. The O-doped PAHs were found to exhibit large saturable absorption and negative sign nonlinear refraction under visible excitation, increasing both with the addition of naphthalene units and with the number of O atoms. Their nonlinear optical response was found to be negligible under infrared excitation. Similar measurements performed on thin films of these PAHs have shown that they maintain their large nonlinear optical response even in the solid state, confirming their high potential for optoelectronic and photonic applications.