217 research outputs found

    Intrapartum sonography of fetal head in second stage of labor with neuraxial analgesia: a literature review and possible medicolegal aftermath

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    Intrapartum ultrasound (IU) is a valid support to obstetric management of fetal head progression in the second stage of labor in nulliparous with neuraxial labor analgesia (NLA). Nulliparous with NLA may have a prolonged the second stage of labor. The aim of this literature review was to evaluate the mode of delivery, as well as maternal and fetal morbidities associated with missed progression of fetal head detected with IU in the second stage of labor in nulliparous women with NLA.MATERIALS AND METHODS: The literature review was performed using PubMed, Cochrane, Medline, EMBASE, Scopus, Google Scholar and book chapters searches to identify relevant articles from 2001 to 2019, evaluating the mode of delivery and morbidities of the second stage of labor. Search terms used were “Intrapartum ultrasound”, “dystocia”, “prolonged labor”, “neuraxial analgesia”, “persistent occiput posterior position”, “asynclitism”, “second stage of labor”, “medico-legal aftermath”. Prolonged second stage was defined as three hours and more. Retrospective case series of women with prolonged second stage of labor with NLA were identified. The primary outcome was the incidence of operative vaginal delivery (OVD) and cesarean delivery (CS). RESULTS: The use of NLA may determine a prolonged second stage of labor (PSSL). IU when compared to the traditional vaginal digital examination (VDE) demonstrated the highest degree of diagnostic accuracy. CONCLUSIONS: The use of IU during NLA can aid in the diagnosis of fetal head progression, station or malposition and malrotation, alerts obstetrician on the possibility of dystocic labor, indicating to stop the drug administration in NLA and shift to OVD or CS. Extending the second stage of labor beyond current American College of Obstetricians and Gynecologists (ACOG) recommendations is beneficial. The ISUOG guidelines recommended the clinical application of IU to diagnose the persistent occiput posterior position (POPP) and asynclitism (A) in dystocic labor and produce photographic evidence of the case. Maternal and neonatal complications, medicolegal consequences and litigation can decrease if the IU device is used as good practice

    Fungos endofĂ­ticos em folhas de Erva-mate (Ilex paraguariensis A. St.-Hill.).

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    Este estudo teve como objetivo analisar o efeito da idade de folhas de erva-mate, colhidas em ervas cultivadas e nativas, sobre a população de fungos endofĂ­ticos. Como resultado verificou-se que ocorre uma maior diversidade de fungos endofĂ­ticos em folhas adultas de erva-mate do que em folhas jovens. A diversidade foi maior nas plantas nativas, com uma microbiota mais abundante, decorrente de um ambiente sombreado e Ășmido, mais propĂ­cio para o seu desenvolvimento, diferente de um agroecossistema. Plantas de erva-mate nativa apresentaram fungos endofĂ­ticos de gĂȘneros com potencial de biocontrole que deveriam ser testados quanto Ă  capacidade de induzir proteção contra pragas e doenças.Notas tĂ©cnicas

    Körner’s septum (petrosquamosal lamina): the anatomical variant or clinical problem?

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    Körner’s septum (KS) or petrosquamosal lamina is a bony lamina beginning at the articular fossa, extending above the middle ear, and running inferiorly and laterally to the facial nerve canal as it proceeds to the mastoid apex. This septum marks the junction of petrous and squamous bones. The paper presents details of the anatomical structure of KS, which is most often present at the level of the head of the malleus and/or the anterior semicircular canal. Attention is paid to embryological aspects of temporal bone development that lead to the formation of KS. Two imaging techniques most frequently used to diagnose KS are described, high resolution computed tomography (HRCT) and cone-beam computed tomography. Also presented is a case report of a 6-year-old patient suffering from chronic otitis media who developed a cholesteatoma due to presence of KS, illustrated with HRCT images and intraoperative capture. The authors describe diagnostic difficulties associated with this anatomical variant in the middle ear. The article also discusses the more frequent occurrence of this clinical problem in ears operated on due to chronic inflammation, retraction pocket or tympanosclerosis in comparison to healthy ears

    The oxidation of ethylene-1,2-d2 over a silver catalyst studied by microwave spectroscopy

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    Stereospecific ethylene-1,2-d2 was oxidized to ethylene oxide-1,2-d2 over Ag catalysts in a flow reactor at 180-280 [deg]C. The epoxide products did not completely randomize for any of the reaction conditions explored. Using a catalyst with good selectivity, 57.5 +/- 1% of the epoxide had the same configuration as the starting material; with a less selective catalyst 54.0 +/- 1% was found. Variation of temperature did not affect the results for either catalyst. It was possible to increase slightly the percentage retention by decreasing the catalyst bed or increasing the flow rate through the reactor. Types of surface processes that can be eliminated by these observations were discussed as well as several hypotheses that can account for the deviations from complete randomization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22627/1/0000177.pd

    Microwave spectrum, structure, dipole moment, and deuterium nuclear quadrupole coupling constants of the acetylene–sulfur dioxide van der Waals complex

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    Thirty‐three a‐ and c‐dipole transitions of the acetylene–SO2 van der Waals complex have been observed by Fourier transform microwave spectroscopy and fit to rotational constants A=7176.804(2) MHz, B=2234.962(1) MHz, C=1796.160(1) MHz. The complex has Cs symmetry with the C2H2 and SO2 moieties both straddling an a–c symmetry plane (i.e., only the S atom lies in the plane). The two subunits are separated by a distance Rcm=3.430(1) Å and the C2 axis of the SO2 is tilted 14.1(1)° from perpendicular to the Rcm vector, with the S atom closer to the C2H2. The dipole moment of the complex is 1.683(5) D. The deuterium nuclear quadrupole hyperfine structure was resolved for several transitions in both C2HD⋅SO2 and C2D2⋅SO2. A lower limit for the barrier to internal rotation of the C2H2 was estimated to be 150 cm−1 from the absence of tunneling splittings. The binding energy was estimated by the pseudo‐diatomic model as 2.1 kcal/mol. A distributed multipole analysis was investigated to rationalize the structure and binding of the complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69970/2/JCPSA6-94-11-6947-1.pd

    Structure of the chlorobenzene–argon dimer: Microwave spectrum and ab initio analysis

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    The rotational spectra of the 35Cl35Cl and 37Cl37Cl isotopes of the chlorobenzene–argon van der Waals dimer have been assigned using Fourier transform microwave spectroscopy techniques. Rotational constants and chlorine nuclear quadrupole coupling constants were determined which confirm that the complex has CsCs symmetry. The argon is over the aromatic ring, shifted from a position above the geometrical ring center towards the substituted carbon atom, and at a distance of about 3.68 Å from it. This distance is 0.1–0.2 Å shorter than the similar distance in the benzene–argon and fluorobenzene–argon complexes. Experimental results are confirmed and explained with the help of second-order MĂžller–Plesset perturbation calculations using a VDZP+diffVDZP+diff basis set. The complex binding energy of the chlorobenzene–argon complex is 1.28 kcal/mol (fluorobenzene–argon, 1.17; benzene–argon, 1.12 kcal/mol) reflecting an increase in stability caused by larger dispersion interactions when replacing one benzene H atom by F or by Cl. The structure and stability of Ar⋅C6H5–XAr⋅C6H5–X complexes are explained in terms of a balance between stabilizing dispersion and destabilizing exchange repulsion interactions between the monomers. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70251/2/JCPSA6-113-20-9051-1.pd

    The microwave spectrum and structure of trimethylamine-monofluoroborane

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    The microwave spectra of the 11B14N, 11B15N, 10B14N and 10B15N species of trimethyl-amine-monofluoroborane have been assigned in order to evaluate the B--N distance. Analysis of the rotational constants using either the single or double substitution methods did not give highly precise results. However, by assuming parameters for the amine moiety found in other complexes and fitting the moments of inertia a value of 1.63 +/- 0.01 A was estimated. The method of predicate observables, an alternative fitting process, resulted in d(BN) = 1.633 +/- 0.006 A along with estimates for the other structural parameters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22697/1/0000251.pd

    Molecular structures of gas‐phase polyatomic molecules determined by spectroscopic methods

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    Spectroscopic data related to the structures of polyatomic molecules in the gas phase have been reviewed, critically evaluated, and compiled. All reported bond distances and angles have been classified as equilibrium (re), average (rz), substitution (rs), or effective (ro) parameters, and have been given a quality rating which is a measure of the parameter uncertainty. The surveyed literature includes work from all of the areas of gas‐phase spectroscopy from which precise quantitative structural information can be derived. Introductory material includes definitions of the various types of parameters and a description of the evaluation procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87746/2/619_1.pd

    The microwave spectrum, ab initio analysis, and structure of the fluorobenzene–hydrogen chloride complex

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    The fluorobenzene–hydrogen chloride π-hydrogen-bonded complex has been studied by high resolution microwave spectroscopy and ab initio calculations. Rotational spectra of the C6H5F–H35Cl,C6H5F–H35Cl, C6H5F–H37Cl,C6H5F–H37Cl, and C6D5F–H35ClC6D5F–H35Cl isotopomers were assigned using pulsed molecular beam techniques in a Fourier-transform microwave spectrometer. The spectra are consistent with a structure of the complex in which the HCl is above the fluorobenzene ring near the ring center, similar to the benzene–HCl prototype dimer. An analysis of the inertial data and the chlorine quadrupole coupling tensor results in two mathematically possible locations for the HCl subunit with respect to the fluorobenzene arising from sign ambiguities in interpreting the spectral constants. One structure has the HCl nearly perpendicular to the aromatic ring; the other has the HCl pointing toward the fluorine end of the ring. Spectral intensities for the ÎŒaÎŒa and ÎŒbÎŒb transitions favor the former configuration. Ab initio calculations (MP2/6-311++G(2df,2pd)+BSSE corrections) indicate that the position of the HCl is driven by electrostatic interactions with the π electrons of the benzene ring. HCl is shifted by 0.16 Å from the center of the ring toward the para-C atom, where the π density is significantly higher. In the equilibrium form, HCl is tilted by ÎŽ=14° from perpendicular to the ring with the hydrogen end toward the para-C atom. The H atom can perform an internal rotation or at least a half-circular libration (barriers smaller than 100 cm−1). An average ÎŽ value of 0.7° is estimated in reasonable agreement with the derived vibrationally averaged value of 3.8°. The complex binding energy ΔEΔE calculated at the CCSD(T)/6-311++G(2df,2pd)+CP(BSSE) level of theory is 2.8 kcal/mol, suggesting a lower ΔEΔE value for benzene–HCl than previously reported. Fluorobenzene–HCl possesses some charge transfer character; however, just 5.5 melectron are transferred from the benzene ring to HCl. In view of this, π–H bonding in fluorobenzene–HCl is predominantly electrostatic rather than covalent in character contrary to claims made in connection with benzene–HCl. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71342/2/JCPSA6-118-20-9278-1.pd
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