Electromagnetic and microwave absorption properties of iron pentacarbonyl pyrolysis-synthesized carbonyl iron fibers

The present study executed iron pentacarbonyl pyrolysis to synthesize one-dimensional structured carbonyl iron fibers (CIFs) via carrier gas induced flow. The obtained CIFs with a diameter of 100–300 nm and length–diameter ratio of more than 20, are actually composed of a large number of nanocrystalline aggregates. We investigated the dependence of the structure, morphology, and static magnetic and electromagnetic properties of the CIFs on the pyrolysis temperatures. CIFs synthesized at 300 °C (denoted as CIF-300) exhibited optimal microwave absorption properties dependent on the fiber structure and well-matched impedance. An optimal reflection loss of −58.1 dB was observed at 13.8 GHz with a matching thickness of 1.43 mm. Furthermore, CIF-300 presented a broad effective absorption bandwidth (RL ≤ −10 dB) of 5.66 GHz with a thickness of 1.44 mm, indicating that it could be applied in practical applications from 3.74 GHz to 18.0 GHz by tuning its thickness from 1.0 mm to 4.0 mm. This paper not only reveals that the CIFs synthesized at 300 °C have great potential application in microwave absorbing materials (MAMs) with thin thicknesses, wide absorption bandwidths, and strong absorption intensities, but also provides a simple approach to prepare metal fibers.

Carbonyl iron fibers synthesized at 300 °C exhibit a minimum RL of −58.1 dB and an effective absorption bandwidth of 5.66 GHz.     

Novel INF2 mutation p. L77P in a family with glomerulopathy and Charcot-Marie-Tooth neuropathy

Background

Mutations in inverted formin, FH2, and WH2 domain containing (INF2) are common causes of dominant focal segmental glomerulosclerosis. INF2 encodes a member of the diaphanous-related formin family, which regulates actin and microtubule cytoskeletons. Charcot-Marie-Tooth neuropathy (CMT) is a group of inherited disorders affecting peripheral neurons. Many reports have shown that glomerulopathy can associate with CMT. However, it has been unclear whether these two processes in the same individual represent one disorder or if they are two separate diseases.

Case diagnosis/treatment

Recently, INF2 mutations were identified in 12 of 16 patients with CMT-associated glomerulopathy, suggesting that these mutations are a common cause of the dual phenotype. In this study, we report two cases of CMT-associated glomerulopathy that both showed INF2 mutations. A novel INF2 mutation, p. L77P, was identified in a family in which the dual phenotype was inherited in a dominant fashion. The pathogenic effect of p. L77P was proposed using a structural homology model. In addition, we identified a patient with a sporadic CMT-associated glomerulopathy carrying a known INF2 mutation: p. L128P.

Conclusions

Our study confirms the link between INF2 mutations and CMT-associated glomerulopathy and widens the spectrum of pathogenic mutations.     

Detection of changes of scar thickness under mechanical loading using ultrasonic measurement

The intervention of pressure therapy on management of hypertrophic scar (HS) after burn is based on the theoretical assumption that the mechanical force added onto the scar tissue will reduce the growth of myofibroblasts which create the collagen clusters and the interstitial space, and to realign fibrous tissues, thus reducing the thickness of HS. In this experimental study, a high frequency ultrasound imaging system (12 MHz) was applied to measure the real time changes of thickness of the post burn HS under a mechanical loading system with similar pressure generated to the scar tissue. The validity of the ultrasound system in measurement of the changes of scar thickness underneath the tissue was tested on the porcine skin in vitro followed by measurement of human skin in vivo. Results showed that the ultrasound measurement of thickness had both good validity (r² = 0.98, p < 0.0001) and good intra-rater reliability (ICC = 0.89). Then, the system was used to test the thickness of 14 human HS samples in vivo among 7 subjects. External loading force with similar pressure range (10–45 mmHg) was then applied to these scar samples via ultrasound probe with rectangular contacting area at 4 cm² and each loading force was maintained unchange for 2 min over the scar tissue. The real time scar thickness was documented. Results showed that the mean scar thickness was found to be significantly decreased when the loading force applied was increased from 5 to 35 mmHg (with 10 mmHg interval) (p < 0.001). A significant negative correlation between the pressure level and scar thickness was observed (r² = 0.96, p = 0.005). The decline of thickness was found more significant between 0 mmHg and 15 mmHg. The findings were in line with the postulate that pressure therapy is effective in reducing the thickness of HS. A long term followup study should be administered to determine the prolonged effect of pressure intervention.     

The use of Biobrane as a delivery method for cultured epithelial autograft in burn patients

Background

Cultured epithelial autografts (CEA) are well described in the literature and are advantageous when dealing with major burns. There have been many methods of CEA application described, however they all have their own difficulties. Here we describe a novel technique of culturing the keratinocytes in Biobrane^®.

Methods

Skin samples were taken from three patients and cultured into pre-confluent keratinocytes. These were seeded in Biobrane^® and applied directly to the patients’ wounds.

Results

Three patients had Biobrane^® with seeded keratinocytes applied. The Biobrane was applied to both donor and burn wound sites, with healing times being similar to the keratinocyte sheets.

Conclusion

The experience of the authors shows that using Biobrane^® seeded with keratinocytes was easier to handle and quicker to produce than confluent sheets of keratinocytes, with no perceived disadvantages to the patients.     

Temporal Trends,Practice Patterns,and Treatment Outcomes for Infected Upper Urinary Tract Stones in the United States

Background

The incidence of infected urolithiasis is unknown, and evidence describing the optimal management strategy for obstruction is equivocal.

Objective

To examine the trends of infected urolithiasis in the United States, the practice patterns of competing treatment modalities, and to compare adverse outcomes.

Design, setting, and participants

A weighted estimate of 396 385 adult patients hospitalized with infected urolithiasis was extracted from the Nationwide Inpatient Sample, 1999–2009.

Outcome measurements and statistical analysis

Time trend analysis examined the incidence of infected urolithiasis and associated sepsis, as well as rates of retrograde ureteral catheterization and percutaneous nephrostomy (PCN) for urgent/emergent decompression. Propensity-score matching compared the rates of adverse outcomes between approaches.

Results and limitations

Between 1999 and 2009, the incidence of infected urolithiasis in women increased from 15.5 (95% confidence interval [CI], 15.3–15.6) to 27.6 (27.4–27.8)/100 000); men increased from 7.8 (7.7–7.9) to 12.1 (12.0–12.3)/100 000. Rates of associated sepsis increased from 6.9% to 8.5% (p = 0.013), and severe sepsis increased from 1.7% to 3.2% (p < 0.001); mortality rates remained stable at 0.25–0.20% (p = 0.150). Among those undergoing immediate decompression, 113 459 (28.6%), PCN utilization decreased from 16.1% to 11.2% (p = 0.001), with significant regional variability. In matched analysis, PCN showed higher rates of sepsis (odds ratio [OR]: 1.63; 95% CI, 1.52–1.74), severe sepsis (OR: 2.28; 95% CI, 2.06–2.52), prolonged length of stay (OR: 3.18; 95% CI, 3.01–3.34), elevated hospital charges (OR: 2.71; 95%CI, 2.57–2.85), and mortality (OR: 3.14; 95%CI, 13–4.63). However, observational data preclude the assessment of timing between outcome and intervention, and disease severity.

Conclusions

Between 1999 and 2009, women were twice as likely to have infected urolithiasis. Rates of associated sepsis and severe sepsis increased, but mortality rates remained stable. Analysis of competing treatment strategies for immediate decompression demonstrates decreasing utilization of PCN, which showed higher rates of adverse outcomes. These findings should be viewed as preliminary and hypothesis generating, demonstrating the pressing need for further study.