Stepwise Reduction of Redox Noninnocent Nitrosobenzene to Aniline via a Rare Phenylhydroxylamino Intermediate on a Thiolate-Bridged Dicobalt Scaffold.

Nitrosobenzene (PhNO) and phenylhydroxylamine (PhNHOH) are of paramount importance because of their involvement as crucial intermediates in the biological metabolism and catalytic transformation of nitrobenzene (PhNO2) to aniline (PhNH2). However, a complete reductive transformation cycle of PhNO to PhNH2 via the PhNHOH intermediate has not been reported yet. In this context, we design and construct a new thiolate-bridged dicobalt scaffold that can accomplish coordination activation and reductive transformation of PhNO. Notably, an unprecedented reversible ligand-based redox sequence PhNO0 ↔ PhNO•- ↔ PhNO2- can be achieved on this well-defined {CoIII(µ-SPh)2CoIII} functional platform. Further detailed reactivity investigations demonstrate that the PhNO0 and PhNO•- complexes cannot react with the usual hydrogen and hydride donors to afford the corresponding phenylhydroxylamino (PhNHO-) species. However, the double reduced PhNO2- complex can readily undergo N-protonation with an uncommon weak proton donor PhSH to selectively yield a stable dicobalt PhNHO- bridged complex with a high pKa value of 13-16. Cyclic voltammetry shows that there are two successive reduction events at E1/2 = -0.075 V and Ep = -1.08 V for the PhNO0 complex, which allows us to determine both bond dissociation energy (BDEN-H) of 59-63 kcal·mol-1 and thermodynamic hydricity (ΔGH-) of 71-75 kcal·mol-1 of the PhNHO- complex. Both values indicate that the PhNO•- complex is not a potent hydrogen abstractor and the PhNO0 complex is not an efficient hydride acceptor. In the presence of BH3 as a combination of protons and electrons, facile N-O bond cleavage of the coordinated PhNHO- group can be realized to generate PhNH2 and a dicobalt hydroxide-bridged complex. Overall, we present the first stepwise reductive sequence, PhNO0 ↔ PhNO•- ↔ PhNO2- ↔ PhNHO- → PhNH2.

The global decline in the sensitivity of vegetation productivity to precipitation from 2001 to 2018.

The sensitivity of vegetation productivity to precipitation (Sppt ) is a key metric for understanding the variations in vegetation productivity under changing precipitation and predicting future changes in ecosystem functions. However, a comprehensive assessment of Sppt over all the global land is lacking. Here, we investigated spatial patterns and temporal changes of Sppt across the global land from 2001 to 2018 with multiple streams of satellite observations. We found consistent spatial patterns of Sppt with different satellite products: Sppt was highest in dry regions while low in humid regions. Grassland and shrubland showed the highest Sppt , and evergreen needle-leaf forest and wetland showed the lowest. Temporally, Sppt showed a generally declining trend over the past two decades (p < .05), yet with clear spatial heterogeneities. The decline in Sppt was especially noticeable in North America and Europe, likely due to the increase in precipitation. In central Russia and Australia, however, Sppt showed an increasing trend. Biome-wise, most ecosystem types exhibited significant decrease in Sppt , while grassland, evergreen broadleaf forest, and mixed forest showed slight increases or non-significant changes in Sppt . Our finding of the overall decline in Sppt implies a potential stabilization mechanism for ecosystem productivity under climate change. However, the revealed Sppt increase for some regions and ecosystem types, in particular global grasslands, suggests that grasslands might be increasingly vulnerable to climatic variability with continuing global climate change.

A Bioinspired Iron-Molybdenum µ-Nitrido Complex and Its Reactivity toward Ammonia Formation.

Multimetallic nitride species, especially those containing biologically related iron or molybdenum, are fundamentally important to understand the nitrogen reduction process catalysed by FeMo-nitrogenase. However, until now, there remains no report about the construction of structurally well-defined FeMo heteronuclear nitrido complex and its reactivity toward ammonia formation. Herein, a novel thiolate-bridged FeII MoVI complex featuring a bent Fe-N≡Mo fragment is synthesized and structurally characterized, which can be easily protonated to form a µ-imido complex. Subsequently, through the proton-coupled electron transfer (PCET) process, this imido species can smoothly convert into the µ-amido complex, which can further undergo reductive protonation to afford the FeMo complex containing an ammine ligand. Overall, we present the first well-defined {Fe(µ-S)2 Mo} platform that can give a panoramic picture for the late stage (N3- →NH2- →NH2- →NH3 ) of biological nitrogen reduction by the heterometallic cooperativity.

Direct observation of the Dzyaloshinskii-Moriya interaction in a Pt/Co/Ni film.

The interfacial Dzyaloshinskii-Moriya interaction in an in-plane anisotropic Pt(4 nm)/Co(1.6 nm)/Ni(1.6 nm) film has been directly observed by Brillouin spectroscopy. It is manifested as the asymmetry of the measured magnon dispersion relation, from which the Dzyaloshinskii-Moriya interaction constant has been evaluated. Linewidth measurements reveal that the lifetime of the magnons is asymmetric with respect to their counter-propagating directions. The lifetime asymmetry is dependent on the magnon frequency, being more pronounced, the higher the frequency. Analytical calculations of the magnon dispersion relation and linewidth agree well with experiments.

Relationship between admission blood urea nitrogen levels and postoperative length of stay in patients with hip fracture: A retrospective study.

To investigate the relationship between admission blood urea nitrogen (BUN) levels and postoperative length of stay (LOS) in hip fracture (HF) patients. This retrospective study retrieved related data from the MIMIC-IV database, of which the laboratory variables were taken preoperatively. The patients were divided into 4 groups according to the BUN quartile levels. After exploring the nonlinear relationship between BUN and LOS by generalized additive model, their connection was further analyzed using the generalized linear models, quantile regression models, and interaction analysis. Receiver operating characteristic curve analysis and decision curve analysis were performed to evaluate its value in predicting first intensive care unit admission and in-hospital mortality. Totally 1274 patients with HF were enrolled in the study. There was a nonlinear relationship between BUN and LOS (P < .05). Besides, BUN was an independent predictor for LOS after adjusting different covariates in 3 models (P < .05). Age served as a significant interactor in this relationship (P < .05). Moreover, receiver operating characteristic curve and decision curve analysis revealed the predictive value of BUN for intensive care unit admission and in-hospital mortality in HF. Admission BUN level as a cost-effective and easy-to-collect biomarker is significantly related to LOS in patients with HF. It helps clinicians to identify potential high-risk populations and take effective preventions before surgery to reduce postoperative LOS.

Prenylated dihydroflavones from the root barks of Morus alba.

Three new prenylated dihydroflavones, moralbaflavones A-C (1-3), together with four known ones (4a/4b, 5, and 6) were isolated from the root barks of Morus alba L. Their structures including the absolute configurations were determined by the analysis of HRMS, NMR, and ECD data. The neuroprotective properties of these prenylated dihydroflavones were screened at the concentration of 10 µM in the sodium nitroprusside-induced rat pheochromocytoma PC-12 cells, and the results showed moralbaflavone C (3) possessed significant neuroprotective activity, being more potent than the positive control edaravone.

New benzofuran neolignans with neuroprotective activity from Phyllanthodendron breynioides.

A pair of undescribed dihydrobenzofuran neolignan enantiomers, (+/-)-phybrenan A (1a/1b), two new benzofuran neolignans, phybrenan B and C (2 and 3), along with four known neolignans (4 - 7) were obtained from the plants of Phyllanthodendron breynioides P. T. Li. The planar structures of all isolates were demonstrated by the analysis of detailed spectroscopic evidence (NMR, HRMS, and IR), and the absolute configurations of novel neolignans were elucidated by combined calculated and experimental ECD data analysis. The neuroprotective activities of all benzofuran neolignans against sodium nitroprusside (SNP)-induced cell death were examined in rat pheochromocytoma PC12 cells. The results exhibited that three compounds (4 - 6) possessed remarkable neuroprotective activities at 10 µM, better than the positive drug edaravone.

Privacy-Preserving Distributed ADMM With Event-Triggered Communication.

This article addresses distributed optimization problems, in which a group of agents cooperatively minimize the sum of their private objective functions via information exchanging. Building on alternating direction method of multipliers (ADMM), we propose a privacy-preserving and communication-efficient decentralized quadratically approximated ADMM algorithm, termed PC-DQM, for solving such type of problems under the scenario of limited communication. In PC-DQM, an event-triggered mechanism is designed to schedule the communication instants for reducing communication cost. Simultaneously, for privacy preservation, a Hessian matrix with perturbed noise is introduced to quadratically approximate the objective function, which results in a closed form of primal vector update and then avoids solving a subproblem at each iteration with possible high computation cost. In addition, the triggered scheme is also utilized to schedule the update of Hessian, which can also reduce computation cost. We theoretically show that PC-DQM can protect privacy but without losing accuracy. In addition, we rigorously prove that PC-DQM converges linearly to the exact optimal solution for strongly convex and smooth objective functions. Finally, numerical simulation is presented to illustrate the effectiveness and efficiency of our algorithm.

A thiolate-bridged ruthenium-molybdenum complex featuring terminal nitrido and bridging amido ligands derived from the N-H and N-N bond cleavage of hydrazine.

Biomimetic di- or multimetallic complexes featuring NxHy species in a sulfur-rich coordination sphere have attracted considerable attention in modelling the possible scenarios of biological nitrogen fixation by nitrogenases. Although the active site of nitrogenases is a complex heterometallic sulfur cluster, the feasibility of NxHy species on different metal sites is scarcely investigated. Herein, we report an unprecedented thiolate-bridged ruthenium-molybdenum complex featuring bridging amido and terminal nitrido ligands obtained by cleaving the N-N and N-H bonds of hydrazine. Remarkably, this RuMo complex is also capable of catalyzing the reduction of hydrazine to ammonia. Overall, this rare activation pattern of hydrazine on a thiolate-bridged RuMo platform provides new insight into the heterometallic cooperativity in nitrogenase.

Nomogram Models Based on the Gene Expression in Prediction of Breast Cancer Bone Metastasis.

Objective: The aim of this study is to design a weighted co-expression network and build gene expression signature-based nomogram (GESBN) models for predicting the likelihood of bone metastasis in breast cancer (BC) patients. Methods: Dataset GSE124647 was used as a training set, while GSE16446, GSE45255, and GSE14020 were taken as validation sets. In the training cohort, the limma package in R was adopted to obtain differentially expressed genes (DEGs) between BC nonbone metastasis and bone metastasis patients, which were used for functional enrichment analysis. After weighted co-expression network analysis (WGCNA), univariate Cox regression and Kaplan-Meier plotter analyses were performed to screen potential prognosis-related genes. Then, GESBN models were constructed and evaluated. The prognostic value of the GESBN models was investigated in the GSE124647 dataset, which was validated in GSE16446 and GSE45255 datasets. Further, the expression levels of genes in the models were explored in the training set, which was validated in GSE14020. Finally, the expression and prognostic value of hub genes in BC were explored. Results: A total of 1858 DEGs were obtained. The WGCNA result showed that the blue module was most significantly related to bone metastasis and prognosis. After survival analyses, GAJ1, SLC24A3, ITGBL1, and SLC44A1 were subjected to construct a GESBN model for overall survival (OS). While GJA1, IGFBP6, MDFI, TGFBI, ANXA2, and SLC24A3 were subjected to build a GESBN model for progression-free survival (PFS). Kaplan-Meier plotter and receiver operating characteristic analyses presented the reliable prediction ability of the models. Cox regression analysis further revealed that GESBN models were independent prognostic predictors for OS and PFS in BC patients. Besides, GJA1, IGFBP6, ITGBL1, SLC44A1, and TGFBI expressions were significantly different between the two groups in GSE124647 and GSE14020. The hub genes had a significant impact on patient prognosis. Conclusion: Both the four-gene signature and six-gene signature could accurately predict patient prognosis, which may provide novel treatment insights for BC bone metastasis.

[Establishment of finite element model of anterior cervical transpedicular system for reconstruction of cervical stability after subtotal resection of two segments of lower cervical spine].

OBJECTIVE: To establish the fixation model of anterior cervical transpedicular system (ACTPS) after subtotal resection of two segments of lower cervical spine(C3-C7) in order to provide a finite element modeling method for anterior cervical reconstruction. METHODS: The CT data of the cervical segment (C1-T1) of a 30-year-old adult healthy male volunteer was collected. Used Mimics 10.0, Rapidform XOR3, HyperMesh 10.0, CATIA5V19 and ANSYS 14.0 to establish the three-dimensional nonlinear complete model of lower cervical spine(C3-C7) as the intact group. The number of units and nodes of the complete model were recorded. After the effectiveness of the complete model was verified, the C5 and C6 vertebral subtotal resection was performed, and the ACTPS model was established as the ACTPS group. The axial force of 75 N and moment couple of 1N·m was loaded on the upper surface of C3 in intact group and ACTPS group, the range of motion(ROM)and stress distribution in states of flexion extension, lateral flexion, rotation was compared between two groups. RESULTS: There were 85 832 elements and 23 612 nodes in the complete model of lower cervical spine(C3-C7) which was established in this experiment. The stress distribution of ACTPS internal fixation model was relatively uniform. Comparing with the intact group, the overall range of motion in ACTPS group was decreased in flexion extension, lateral flexion and rotation directions, and the corresponding compensation of adjacent C3,4 segment was increased slightly. CONCLUSION: The stress distribution of ACTPS fixation system is uniform, there is no stress concentration area at the joint of screw and titanium plate, and the fracture risk of internal fixation is low. It is suitable for stability reconstruction after anterior decompression of two or more cervical segments.

Vegetation resistance and resilience to a decade-long dry period in the temperate grasslands in China.

The duration of climate anomalies has been increasing across the globe, leading to ecosystem function loss. Thus, we need to understand the responses of the ecosystem to long-term climate anomalies. It remains unclear how ecosystem resistance and resilience respond to long-term climate anomalies, for example, continuous dry years at a regional scale. Taking the opportunity of a 13-year dry period in the temperate grasslands in northern China, we quantified the resistance and resilience of the grassland in response to this periodic dry period. We found vegetation resistance to the dry period increased with mean annual precipitation (MAP), while resilience increased at first until at MAP of 250 mm and then decreased slightly. No trade-off between resistance and resilience was detected when MAP < 250 mm. Our results highlight that xeric ecosystems are most vulnerable to the long-term dry period. Given expected increases in drought severity and duration in the coming decades, our findings may be helpful to identify vulnerable ecosystems in the world for the purpose of adaptation.

(2S*)-2-Ammonio-3-(1H-indol-3-yl)propionate pyridine-2,4-dicarboxylic acid ethanol solvate.

In the title compound, C(11)H(12)N(2)O(2)·C(7)H(5)NO(4)·C(2)H(6)O, the (2S*)-2-amino-3-(1H-indol-3-yl)propionic acid is present in the zwitterionic form. In the crystal structure, 2-amino-3-(1H-indol-3-yl)propionic acid mol-ecules and pyridine-2,4-dicarb-oxylic acid mol-ecules are linked through strong inter-molecular O-H⋯O and N-H⋯O hydrogen bonds, forming layers parallel to (100). The layers are linked through the ethanol mol-ecules via somewhat weaker inter-molecular O-H⋯O and N-H⋯O hydrogen bonds, forming thus a three-dimensional network. Weak C-H⋯O and N-H⋯N hydrogen bonding and π-π inter-actions between the aromatic rings are also present.

[Evaluation of the effect of post-abortion counseling and education among unmarried abortion adolescents].

OBJECTIVE: To find out the requirement and to evaluate the effect of post-abortion counseling and education (PACE) among unmarried abortion adolescents. METHODS: The subjects of the study were unmarried adolescents from 10 to 24 years of age who wanted induced abortion in the Second Affiliated Hospital of Sun Yat-sen University from December 2007 to April 2008. Totally 122 subjects received the intervention of PACE were considered as intervention group. Meanwhile, 67 subjects refused the intervention of PACE were considered as no intervention group. Two groups were both investigated the requirements of PACE before abortion and were followed-up at one year after abortion. RESULTS: 97.4% (184/189) of 189 unmarried abortion adolescents were willing to receive PACE, 48.1% (91/189) of them hoped to receive PACE when saw the doctor, 72.0% (136/189) of them required face-to-face counseling during PACE. During the year after abortion, 74% (57/77) cases in intervention group and 24% (10/41) cases in no intervention group took effective contraception (P < 0.01), while 1% (1/77) of intervention group and 10% (4/41) of no intervention group had unwanted pregnancy. There were significant different for the rate of unwanted pregnancy between two groups (P = 0.034). CONCLUSION: For unmarried abortion adolescents, the intervention of PACE may markedly increase the rate of effective contraception used and decrease the rate of another unwanted pregnancy.

Iliac screw for reconstructing posterior pelvic ring in Tile type C1 pelvic fractures.

BACKGROUND: It is often difficult to achieve stable fixation in Tile type C1 pelvic fractures and there is no standard fixation technique for these types of injuries. HYPOTHESIS: Iliac screw fixation can be used for treating Type C1 pelvic fractures. PATIENTS AND METHODS: A retrospective review was performed on 47 patients who underwent iliac screw fixation in posterior column of ilium (PCI) for Tile type C1 pelvic fractures from July 2007 to December 2014. All patients were treated with fracture reduction, sacral nerve root decompression (if needed), internal fixation by iliac screw and connecting rod. The data on surgical time, intraoperative bleeding volume, postoperative neurologic functions and postoperative complications were analyzed. Patients were follow-up for at least 12months. RESULTS: The mean surgical time was 148minutes, and the mean intraoperative bleeding volume was 763ml. Patients were encouraged in-bed activities immediately after surgery. The postoperative Majeed functional score was 48-100 points (mean 80.2), corresponding to an excellent and good recovery of 91.5%. Postoperative X-radiographs and CT scans indicated satisfactory fracture reduction. DISCUSSION: Iliac screw fixation combined with sacral nerve canal decompression could effectively restore pelvic alignment and improve neurological functions for complex pelvic trauma.

[Modified tubo-uterine implantations for proximal tubal occlusive infertility after femal sterilization with mucilago phenol].

OBJECTIVE: To explore the effects of modified tubo-uterine implantations performed on women with proximal tubal occlusive infertility after femal sterilization with mucilago phenol. METHODS: Two hundred and eight infertile women who were admitted to the Second Affiliated Hospital of Sun Yat-sen University between 1986 and 2004 were included. They all accepted modified tubo-uterine implantation after occlusion of fallopian tubes with mucilago phenol. RESULTS: It was found that the occlusions were all located in the interstitial portion or isthmic portion of the fallopian tubes. Different degrees of pelvic adhesions were found in 65 cases. Fifty-seven cases were slightly adhesive, seven cases were of moderate degree and one case was severe. One hundred and ninety-nine cases were followed up after operations (95.7%). One hundred and ninety-three women accepted hydrotubation in the following month just after the operation and 185 women were found to be unobstructed (95.8%). One hundred and forty-three women became pregnant, the pregnant rate being 71.9% (143/199). One hundred and twenty-five women had term deliveries (87.4%), three women were in early pregnancy and two in midtrimester pregnancy. Eleven women had spontaneous abortion (7.7%). Two women had tubal pregnancy (1.0%). None of the 199 cases had any signs of endometriosis. CONCLUSIONS: Modified tubo-uterine implantations are quite effective for proximal tubal occlusive infertility. It may be a favorable method for such kind of tubal occlusions.

Analysis of the mechanism by which nerve growth factor promotes callus formation in mice with tibial fracture.

The aim of the present study was to analyze the mechanism by which nerve growth factor (NGF) promotes callus formation in mice with tibial fracture. NGF transgenic homozygotic mice and NGF wild homozygotic mice were selected to construct non-stabilized fracture model of tibia. The mice were sacrificed on days 7, 14 and 21, respectively, and each group had a sample with 8 mice at each point in time. X-ray radiography and safranin fast green were used to observe fracture healing and in situ hybridization was used to examine the NGF mRNA expression of tibia at each phase of fracture healing. Tartrate-resistant acid phosphatase (TRAP) staining of callus tissue and the expression level of TRAP mRNA were combined to observe osteoclast formation. COL2A1, a chondrocyte differentiation-related gene in callus, and the mRNA level of SOX9 were combined to observe chondrocyte differentiation. It was found that under X-ray radiography, the fracture of NGF transgenic homozygotic mice healed in advance (P<0.05). Cartilage and bone tissue were identified by safranin and fast green staining. The residual cartilage on the callus tissue of NGF transgenic homozygotic mice had decreased significantly (P<0.05). The NGF mRNA expression level in each phase of callus formation of NGF transgenic homozygotic mice was significantly higher than that of the wild group (P<0.05). The number of positive cells in NGF-TRAP staining at each time point after fracture and the NGF mRNA expression level was markedly higher than that of the wild group, and the expression levels of COL2A1 and SOX9 mRNA were distinctively higher than that of the wild group. In conclusion, NGF potentially improves the healing of tibial fracture by osteoclast formation. Additionally, an increase in the number of osteoblasts in the NGF transgenic homozygotic mice compared with the wild-type mice may be achieved by cartilage differentiation due to NGF increasing the COL2A1 and SOX9 mRNA expression levels.

Electrorheological behavior of copper phthalocyanine-doped mesoporous TiO2 suspensions.

A type of anhydrous electrorheological (ER) material of copper phthalocyanine (CuPC)-doped mesoporous TiO2 was synthesized by in situ micelle-assisted incorporation CuPC during mesoporous TiO2 synthesis. TEM, XRD and the nitrogen adsorption-desorption isotherms demonstrated that the material had mesoporous structure and an anatase framework. The ER behavior of the suspensions of CuPC-doped mesoporous TiO2 in silicone oil with the different volume fractions was investigated under an applied electric field. It is found that the suspensions showed visible electrorheological behavior which were compared with that of pure TiO2. The dopants of CuPC molecules within the mesochannel of TiO2 mesoporous sieve improved the conductivity of the particles and produced a proper conductivity of approximately 10(-7) S m(-1). Dielectric spectra of the ER fluid were measured to examine the peak of epsilon'' should appear in the frequency range of 10(2)-10(5) Hz and have a large Deltaepsilon' in this frequency range. Therefore, the both properties may make a conjunct effect on electrorheological behavior.

[Study on causes and treatment of repeated vulvovaginitis in girlhood].

OBJECTIVE: To explore the causes and treatment of repeated vulvovaginitis in girlhood in order to improve its prevention and treatment. METHODS: Fifty-one girls with repeated vulvovaginitis (age < or = 10 years) admitted to The Second Affiliated Hospital of Sun Yat-sen University from Jan. 1990 to Nov. 2004 were reviewed retrospectively. RESULTS: We found 28 girls (55%) suffering from non-specific vulvovaginitis and 14 ones (27%) suffering from posterior recto-vaginal fistula with in 51 patients. Five girls (10%) were smitten with vulval ulcer and 3 ones (6%) had been were found with vaginal foreign bodies. One girl (2%) was smitten with adhesion of labia minora. The vaginal discharges taken from 21 girls were cultured. Seventeen cases found bacteria. The positive rate of bacteria culture in the 21 cases reached 81%, in which, E.coli accounted for 5 cases (24%), staphylococcus and streptococcus accounted for 3 cases (14%) respectively. Patients suffering from non-specific vulvovaginitis and vulval ulcer accepted external lotion, antibiotic ointment or combining with antibiotics. Patients suffering from posterior recto-vaginal fistula accepted fistulectomy. Three girls who found vaginal foreign bodies took out of foreign bodies by hysteroscope. Fifty-one girls all were cured after appropriate therapy. CONCLUSIONS: Vulvovaginitis is the most common gynecologic diagnosis in girlhood. The principal cause of repeated invasion is non-specific vulvovaginitis and the secondly one is posterior recto-vaginal fistula. It need overhaul during the diagnosis. It is very availability to use hysteroscopy and do bacteria culture + antibiotic sensitivity test for repeated pediatric vulvovaginitis.

[Diagnosis and treatment of endometriosis in adolescents].

OBJECTIVE: To discuss the clinical feature, diagnosis and treatment options of adolescent endometriosis. METHODS: The records of adolescent patients with endometriosis (11-20 years old) who were admitted to First, Second and Third Affiliated Hospital of Zhongshan University and Guangdong Provincial People's Hospital between 1990 and 2003 were retrospectively reviewed. RESULTS: Forty-three patients were diagnosed as endometriosis either by laparotomy or laparoscopy. The chief symptoms leading to the diagnosis were palpable pelvic mass (18/43), dysmenorrhea (15/43), chronic pelvic mass (10/43) and acute pelvic pain (4/43). The majority of patients (53%) presented with the revised AFS-r classification stage III, 8 cases (19%) presented with stage I, 3 cases (7%) with stage II and 9 cases (21%) with stage IV. Nine cases (21%) had complicated genital tract abnormalities. Conservative operations, including salpingo-oophorectomy ins cases, ovarian cystectomy in 31 cases and laparoscopic vaporization in 8 cases, were performed. Surgeries were followed by hormonal suppression using oral contraceptives in a continuous or cyclic manner. CONCLUSIONS: Adolescent endometriosis may occur around 4.6 years after menarche. The chief symptoms are palpable pelvic mass and dysmenorrhea. The treatment of endometriosis in adolescence does not differ principally from that in adult women. In the treatment of endometriosis and for the prevention of recurrence, it is recommended to give 3-6 months of oral contraceptives.