730 research outputs found
Recent Innovations & Daily Problems. A new prosthesis in inguinal hernia repair:preliminary results of a pilot study.
Introduction: Elective surgery for inguinal hernia is affected by very
low mortality « 1 per 10000 operation); in contrast, when surgery
is carried out for complicated inguinal hernia, risks of postoperative
complication are higher. TAPP is a world-wide accepted surgical practice
in the treatment of elective bilateral or recurrent inguinal hernia,
above all in young patients. Few exploratory studies were published on
laparoscopic approach in the treatment of urgent complicated inguinal
hernia. Aim of this study was to analyze feasibility (operative time,
conversion rate), safety (postoperative morbidity, length of hospital
stay) and quality of life (acute and chronic pain, return to work) of
trans-abdominal pre-peritoneal laparoscopic hernia repair in acute
incarcerated inguinal hernia. Rationale of laparoscopic trans-abdominal
approach is the easier hernia reduction under vision and a better
exploration of the abdominal cavity.
Methods: from September 2012 to September 2013, 15 consecutive
patients admitted in emergency at the Division of General Surgery of
University "Sapienza", Polo Pontino, for acute incarcerated inguinal
hernia were submitted to TAPP using 3 trocars (1 of 10 mm and 2 of
5mm) and polyester prosthesis fixed by fibrin glue. Exclusion criteria
for laparoscopic approach were age III, previous
abdominal surgery, signs of strangulated hernia. All of them were
evaluated for operative time, conversion rate, postoperative morbidity,
organ resection or other surgery required. All patients were scored for
pain by Visual Analogic Scale (VAS) during postoperative in hospital
stay at 7 days, 1,6 and 12 months after surgery.
Results: median follow-up was 16 months and 12 as minimum. In all
cases reduction of hernia was always possible and none conversion
to open surgery was recorded, median operative time was 89 minutes
(55-137 as range), omental resection was carried out in one patient
(6,6%), no other organ resections needed, whereas contralateral hernia
was diagnosed and repaired at the same time in 4 patients (26,6%). No
major complications were observed, median blood loss was 100 ml,
minor morbidity was contained to 18% represented by fever and
wound infection of surgical umbilical scar. Median in hospital stay
was 1,5 days with 1-5 days as range. Postoperative median acute pain,
measured by visual analogic scale (VAS), was 2 (range:0-4), none
patient referred any pain during follow-up. Median time of return to
work was 6,5 days, ranged between 3 to 15 days. Patients' compliance
to treatment and to follow-up was complete as well their satisfaction. Conclusions: In centres skilled for laparoscopy in emergency, TAPP
could be considered a feasible and safe technique. In well-selected
patients (especially if emolled in controlled clinical trial) TAPP could
represent an alternative surgical approach for complicated incarcerated inguinal hernia to conventional open surgery even in urgency. The
main advantages of laparoscopic approach are the ability to perform
surgical hernia reduction under vision, a better exploration and evaluation
of abdominal cavity and diagnosis and treatment of eventual
contralateral defect of wall, otherwise often missed. Finally, the good
control of acute and chronic pain, faster return to normal activity and
work, better aesthetic results contributed to total satisfaction and compliance
of the patients
Disclosure of Maternal HIV Status to Children: To Tell or Not To Tell . . . That Is the Question
HIV-infected mothers face the challenging decision of whether to disclose their serostatus to their children. From the perspective of both mother and child, we explored the process of disclosure, providing descriptive information and examining the relationships among disclosure, demographic variables, and child adjustment. Participants were 23 mothers and one of their noninfected children (9 to 16 years of age). Sixty-one percent of mothers disclosed. Consistent with previous research, disclosure was not related to child functioning. However, children sworn to secrecy demonstrated lower social competence and more externalizing problems. Differential disclosure, which occurred in one-third of the families, was associated with higher levels of depressive and anxiety symptoms. Finally, knowing more than mothers had themselves disclosed was related to child maladjustment across multiple domains. Clinical implications and the need for future research are considered
Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA
Deep-inelastic positron-proton interactions at low values of Bjorken-x down
to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons
are studied with the H1 experiment at HERA. The inclusive cross section for
pi^0 mesons produced at small angles with respect to the proton remnant (the
forward region) is presented as a function of the transverse momentum and
energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x.
Measurements are also presented of the transverse energy flow in events
containing a forward pi^0 meson. Hadronic final state calculations based on QCD
models implementing different parton evolution schemes are confronted with the
data.Comment: 27 pages, 8 figures and 3 table
Searches at HERA for Squarks in R-Parity Violating Supersymmetry
A search for squarks in R-parity violating supersymmetry is performed in e^+p
collisions at HERA at a centre of mass energy of 300 GeV, using H1 data
corresponding to an integrated luminosity of 37 pb^(-1). The direct production
of single squarks of any generation in positron-quark fusion via a Yukawa
coupling lambda' is considered, taking into account R-parity violating and
conserving decays of the squarks. No significant deviation from the Standard
Model expectation is found. The results are interpreted in terms of constraints
within the Minimal Supersymmetric Standard Model (MSSM), the constrained MSSM
and the minimal Supergravity model, and their sensitivity to the model
parameters is studied in detail. For a Yukawa coupling of electromagnetic
strength, squark masses below 260 GeV are excluded at 95% confidence level in a
large part of the parameter space. For a 100 times smaller coupling strength
masses up to 182 GeV are excluded.Comment: 32 pages, 14 figures, 3 table
Search for Doubly-Charged Higgs Boson Production at HERA
A search for the single production of doubly-charged Higgs bosons H^{\pm \pm}
in ep collisions is presented. The signal is searched for via the Higgs decays
into a high mass pair of same charge leptons, one of them being an electron.
The analysis uses up to 118 pb^{-1} of ep data collected by the H1 experiment
at HERA. No evidence for doubly-charged Higgs production is observed and mass
dependent upper limits are derived on the Yukawa couplings h_{el} of the Higgs
boson to an electron-lepton pair. Assuming that the doubly-charged Higgs only
decays into an electron and a muon via a coupling of electromagnetic strength
h_{e \mu} = \sqrt{4 \pi \alpha_{em}} = 0.3, a lower limit of 141 GeV on the
H^{\pm\pm} mass is obtained at the 95% confidence level. For a doubly-charged
Higgs decaying only into an electron and a tau and a coupling h_{e\tau} = 0.3,
masses below 112 GeV are ruled out.Comment: 15 pages, 3 figures, 1 tabl
Deep-Inelastic Inclusive ep Scattering at Low x and a Determination of alpha_s
A precise measurement of the inclusive deep-inelastic e^+p scattering cross
section is reported in the kinematic range 1.5<= Q^2 <=150 GeV^2 and
3*10^(-5)<= x <=0.2. The data were recorded with the H1 detector at HERA in
1996 and 1997, and correspond to an integrated luminosity of 20 pb^(-1). The
double differential cross section, from which the proton structure function
F_2(x,Q^2) and the longitudinal structure function F_L(x,Q^2) are extracted, is
measured with typically 1% statistical and 3% systematic uncertainties. The
measured partial derivative (dF_2(x,Q^2)/dln Q^2)_x is observed to rise
continuously towards small x for fixed Q^2. The cross section data are combined
with published H1 measurements at high Q^2 for a next-to-leading order DGLAP
QCD analysis.The H1 data determine the gluon momentum distribution in the range
3*10^(-4)<= x <=0.1 to within an experimental accuracy of about 3% for Q^2 =20
GeV^2. A fit of the H1 measurements and the mu p data of the BCDMS
collaboration allows the strong coupling constant alpha_s and the gluon
distribution to be simultaneously determined. A value of alpha
_s(M_Z^2)=0.1150+-0.0017 (exp) +0.0009-0.0005 (model) is obtained in NLO, with
an additional theoretical uncertainty of about +-0.005, mainly due to the
uncertainty of the renormalisation scale.Comment: 68 pages, 24 figures and 18 table
Measurement of the branching ratio of pi^0 -> e^+e^- using K_L -> 3 pi^0 decays in flight
The branching ratio of the rare decay pi^0 -> e^+e^- has been measured in
E799-II, a rare kaon decay experiment using the KTeV detector at Fermilab. The
pi^0's were produced in fully-reconstructed K_L -> 3 pi^0 decays in flight. We
observed 275 candidate pi^0 -> e^+e^- events, with an expected background of
21.4 +- 6.2 events which includes the contribution from Dalitz decays. We
measured BR(pi^0 -> e^+e^-, x>0.95) = (6.09 +- 0.40 +- 0.24) times 10^{-8},
where the first error is statistical and the second systematic. This result is
the first significant observation of the excess rate for this decay above the
unitarity lower bound.Comment: New version shortened to PRL length limit. 5 pages, 4 figures.
Published in Phys. Rev. Let
Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant
Jet event rates in deep inelastic ep scattering at HERA are investigated
applying the modified JADE jet algorithm. The analysis uses data taken with the
H1 detector in 1994 and 1995. The data are corrected for detector and
hadronization effects and then compared with perturbative QCD predictions using
next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2)
is determined evaluating the jet event rates. Values of alpha_S(Q^2) are
extracted in four different bins of the negative squared momentum
transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the
renormalization group equation to these several alpha_S(Q^2) values results in
alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys.
J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4
Multiplicity Structure of the Hadronic Final State in Diffractive Deep-Inelastic Scattering at HERA
The multiplicity structure of the hadronic system X produced in
deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic
system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY
vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant
mass M_X of the system X. Results are presented on multiplicity distributions
and multiplicity moments, rapidity spectra and forward-backward correlations in
the centre-of-mass system of X. The data are compared to results in e+e-
annihilation, fixed-target lepton-nucleon collisions, hadro-produced
diffractive final states and to non-diffractive hadron-hadron collisions. The
comparison suggests a production mechanism of virtual photon dissociation which
involves a mixture of partonic states and a significant gluon content. The data
are well described by a model, based on a QCD-Regge analysis of the diffractive
structure function, which assumes a large hard gluonic component of the
colourless exchange at low Q^2. A model with soft colour interactions is also
successful.Comment: 22 pages, 4 figures, submitted to Eur. Phys. J., error in first
submission - omitted bibliograph
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