Search results for "Ull"
showing 10 items of 3152 documents
Über methylsubstituierte polyphenylene
1951
Es werden Versuche geschildert, die zur Darstellung von loslichen, stabchenformigen Molekulen, namlich para-verketteten, methylsubstituierten Polyphenylenen fuhren sollen. 4.4′-Dijod-3.3′-dimethyl-diphenyl wurde nach Ullmann mit Kupferpulver unter verschiedenen Bedingungen kondensiert und die erhaltenen loslichen, methylierten Polyphenylene fraktioniert. Ultrazentrifugale und osmotische Messungen ergeben fur die hochstmolekularen Fraktionen Molekulargewichte bis zu 300000. Kryoskopische Untersuchungen liefern anomale Molekulargewichte. Die Ergebnisse der Viskositats-, Sedimentations und Diffusionsmessungen werden im Hinblick auf die Gestalt der Molekule diskutiert. Die unter den angewandten…
High-resolution photoacoustic Raman spectroscopy of gases
1992
A high-resolution photoacoustic Raman spectroscopy experiment is described. The resolution achieved by using two single-mode pulsed lasers is about 0.0054 cm −1 (full width at half maximum intensity). The experiment was tested first on the v 1 /2v 2 bands of CO 2 and gave an increase of at least about one order of magnitude in the signal-to-noise ratio with respect to stimulated Raman spectroscopy at low pressure (ca. 10 Torr ≃ 1.3 kPa). The sensitivity is also demonstrated by the study of the weak hot band v 1 +v 2 −v 2 of CO 2 . In both cases, the experimental line shape is well reproduced by taking into account Doppler and collisional effects. A comparison with CARS spectra was also made
Intensity-modulated extended-field chemoradiation plus simultaneous integrated boost in the pre-operative treatment of locally advanced cervical canc…
2015
Objective: To investigate the feasibility and determine the recommended pre-operative intensity-modulated radiotherapy (IMRT) dose of extended-field chemoradiation along with simultaneous integrated boost (SIB) dose escalation. Methods: A radiation dose of 40Gy over 4 weeks, 2Gy/fraction, was delivered to the tumour and the lymphatic drainage (planning target volume, PTV3), which encompassed a volume larger than standard (common iliac lymphatic area up to its apex, in front of the L3 vertebra), concurrently with chemotherapy (cisplatin and 5-fluorouracil). Radiation dose was escalated to the pelvis (PTV2) and to the macroscopic disease (PTV1) with the SIB-IMRT strategy. Three dose levels we…
Does Childhood Psychological Abuse Contribute to Intimate Partner Violence Victimization? An Investigation Using the Childhood Experience of Care and…
2018
International audience; Although psychological abuse is recognized as a particularly insidious form of child abuse, research on the impact of this type of abuse related to intimate partner violence (IPV) is scant. This study examined the contribution of childhood psychological abuse to IPV in female victims and non-victims. Furthermore, it investigated the role of cumulative abuse in predicting IPV. The study included 38 women victims of IPV and 40 non-IPV women. All participants were investigated using the Childhood Experience of Care and Abuse Interview (CECA); the Revised Conflict Tactics Scale (CTS2) and the IPV History Interview were used to assess IPV in the last year and lifetime, re…
Poly-Victimization in Polish Adolescents: Risk Factors and the Moderating Role of Coping.
2018
This study aimed to investigate the prevalence of poly-victimization in Polish adolescents and assess factors associated with poly-victimization risk across different ecological levels. This study further examined whether coping styles could moderate the impact of poly-victimization on emotional well-being. Participants were 454 adolescents, aged between 13 and 19 years, from an urban region of Poland. Adolescents completed self-report measures assessing community, school, and family risks, along with a peer nomination task measuring social preference. Teachers also completed a measure assessing adolescent problem behaviors. Findings revealed that the majority of the sample (70%) experience…
Loneliness, Depressive Mood and Cyberbullying Victimization in Adolescent Victims of Cyber Dating Violence.
2020
Currently, cyber dating violence (CDV) is a serious health problem among adolescents due to their frequent use of communication technologies in their romantic relationships including the use of these technologies to perpetrate dating violence. However, research on this topic is recent and more studies about victims&rsquo
La gaozhong o scuola secondaria di secondo grado nel sistema scolastico della Repubblica Popolare Cinese
2020
L'articolo inquadra la scuola secondaria di secondo grado, gaozhong, nel sistema scolastico cinese. Il XX secolo in Cina si caratterizza per una successione di trasformazioni epocali che nel tempo hanno cambiato il volto del Paese. In particolare, dopo la conclusione del lungo e contraddittorio decennio della Rivoluzione culturale (1966-1976), che aveva determinato la chiusura delle scuole secondarie di ogni grado e delle università con la successiva dispersione degli studenti nelle aree rurali, è stato necessario ricostruire il sistema scolastico nella sua interezza. Infatti, le scuole non erano più praticabili, molti professori erano stati sottoposti a critica e gli studenti erano stati a…
Toxicity of fullerene (C60) to sediment-dwelling invertebrate Chironomus riparius larvae
2011
An environmentally realistic method to test fullerene (C(60) ) toxicity to the benthic organism Chironomus riparius was created by allowing suspended fullerenes to settle down, making a layer on top of the sediment. To test the hypothesis that higher food concentrations will reduce toxic responses, two food concentrations were tested (0.5 and 0.8% Urtica sp.) in sediment containing fullerene masses of 0.36 to 0.55 mg/cm(2) using a 10-d chronic test. In the 0.5% food level treatments, there were significant differences in all growth-related endpoints compared with controls. Fewer effects were observed for the higher food treatment. Fullerene agglomerates were observed by electron microscopy …
Pharmacology of the Sphincter of Oddi
1988
The sphincter of Oddi is the smooth muscle connection between the bile duct and the duodenum. Its physiological function is associated with a regular motility characterized by phasic contractions superimposed on the sphincter of Oddi baseline pressure. Recently introduced ERCP-manometry permits further studies of sphincter of Oddi pharmacology. A number of drugs have so far been studied. Sedatives of the diazepam type had no effect on the sphincter, while butylscopolaminium bromide, a typical neurotropic agent, brings about cessation of the sphincter motility for 3-8 minutes. Hymecromon lowered the sphincter baseline pressure from 9.8 to 7.8 mmHg. A 1.2 mg sublingual dose of nitroglycerin, …
A critical assessment of methods for the determination of the shear stress amplitude in multiaxial fatigue criteria belonging to critical plane class
2015
Abstract Multiaxial high cycle fatigue criteria based on the critical plane approach necessitate unambiguous definitions of the amplitude and mean value of the shear stress (τa and τm) acting on the material planes. Four of the existing definitions relate the values of τa and τm to a geometrical element of the curve described by the tip of the shear stress vector (curve Ψ), respectively, the radius of the Minimum Circumscribed Circle, the Longest Chord, the Longest Projection, the diagonal of the Maximum Rectangular Hull (MRH). In this paper a critical assessment of the above definitions is proposed, focusing on that based on the concept of MRH, which is the most recently developed. The mai…