Measurement of muon neutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

Measurement of muon antineutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We have isolated ν(μ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.

Hypoxaemia after osteosynthesis of hip fractures

Hypoxaemia may cause postoperative confusion after operations for hip fractures in elderly patients. Twenty-two consecutive patients, with a median age of 73 years, had fractures fixed with a sliding hip screw within 48 hours of admission. The incidence of hypoxaemia was investigated postoperatively using a pulse oximeter. We have demonstrated that this complication occurs frequently on the first day and severe hypoxaemia can be prevented by supplementary oxygen therapy. Our results support the hypothesis that postoperative confusion can be caused by hypoxaemia.

Maltreatment of children born to teenage mothers: a comparison between the 1960s and 1980s

OBJECTIVE

To determine whether the rates or the reporting of maltreatment of children born to teenage mothers changed from the 1960s to the 1980s.

DESIGN

Comparison of two cohorts.

SETTING

Ambulatory services of Yale-New Haven Hospital, New Haven, Conn.

PATIENTS

Consecutive children born to black teenage mothers; the "early" cohort comprised 148 children born from September 1967 through June 1969, and the "late" cohort, 159 children born from October 1979 through December 1981.

OUTCOME MEASURES

Each injury for which the child was medically evaluated from birth to 5 years of age was categorized by predefined criteria as follows: maltreatment (abuse, neglect, or sexual abuse), household violence, unintentional injury-neglect, unintentional injury, or insufficient information.

RESULTS

The rates of maltreatment in the early cohort and in the late cohort were similar: 12.8% versus 10.7% (relative risk (RR) = 0.83; 95% confidence interval (CI) = 0.45, 1.54). The rates of unintentional injury also were similar: 52% in the early cohort versus 60% in the late cohort (RR = 1.17; 95% CI = 0.96, 1.43). In contrast, 30% of the episodes of maltreatment were reported to the state protective service agency in the early cohort versus 65% of episodes in the late cohort (RR = 2.14; 95% CI = 1.08, 4.26).

CONCLUSION

Among children born to teenage, black, inner-city women, the rates of child maltreatment are similar from the late 1960s to the 1980s. The increased rates of reporting of maltreatment reflect increased rates of recognition by clinicians, rather than true increases in prevalence.

Diagnostic value of ultrasound in scaphoid fractures

Diagnostic ultrasound was used in 103 patients with a clinically suspected fracture of the scaphoid bone in order to achieve an early diagnosis. There were 48 women and 55 men aged 10-75 years (mean 31.4 years) tested with ultrasound. Of the patients, 72 were tested within 3 days after injury the remainder between 4 and 42 days. Fracture was confirmed radiologically in 27. We found that the ultrasound test, applied with a frequency of 1 MHz and intensity of 0.5 W/cm2 and 2.0 W/cm2 for 30s, had a sensitivity of 37 per cent and a specificity of 61 per cent. We thus conclude that ultrasound is not suitable for early diagnosis of scaphoid fracture.

Tibial plateau fractures. A comparison of conservative and surgical treatment

We evaluated the long-term results of 109 tibial plateau fractures, 61 treated by skeletal traction and early knee movement and 48 treated by surgery, at an average follow-up of 70 months. The functional results were much the same, though meniscectomy had been performed in almost half of the surgical patients. Time in bed and duration of hospital stay were clearly shorter after surgery (p less than 0.0001). We concluded that conservative management is a valid alternative to surgery, but should probably be reserved for cases where operation is undesirable. Future studies should compare surgery without meniscectomy and conservative treatment using cast braces to reduce the time in traction.

Hot air coagulation: an animal study

Aerothermotherapy with a Leister hot air coagulator was tested in a simulated operation field followed by a prospective double-blind animal pilot study to examine hemostasis and tissue reactions. Two symmetrical incisions were made on the back of 5 rabbits. One of the two wounds was randomised to aerothermotherapy. The temperature rise in the wound was registered by thermistors. No wound complications were observed. Five days postoperatively all wounds were excised for histological examination. A superficial muscular cell necrosis was observed in 3 of the 5 hot-air-coagulated back wounds. Liver resection was performed in 2 of the rabbits. The bleeding from the resection surface was stopped effectively by aerothermotherapy. Combination of the hot air temperature, the distance to the tissue and the application time was crucial for avoiding burns. If these factors are observed, the hot air coagulator may be used as a supplement to conventional methods of hemostasis.

Management of closed fractures

A closed fracture is defined as a break in the continuity of the bone which does not communicate with the outside of the body. Management of the patient includes a thorough assessment of the fracture, evaluation of other injuries, and reduction as indicated. The patient is carefully observed for complications should problems arise.