Quantitative demodulation of distributed low-frequency vibration based on phase-shifted dual-pulse phase-sensitive OTDR with direct detection.

Phase-sensitive optical time-domain reflectometry (Φ-OTDR) has been proposed for distributed vibration sensing purpose over recent years. Emerging applications, including seismic and hydroacoustic wave detection, demand accurate low-frequency vibration reconstruction capability. We propose to use the direct-detection Φ-OTDR configuration to achieve quantitative demodulation of external low-frequency vibrations by phase-shifted dual-pulse probes. Simultaneous pulsing and phase shifting modulation is realized with a single acousto-optic modulator to generate such probes, relaxing the need for an additional optical phase modulator. In the experiments, vibrations with frequency as low as 0.5 Hz are successfully reconstructed with 10 m spatial resolution and 35 dB signal-to-noise ratio. Excellent linearity and repeatability are demonstrated between the optical phase demodulation results and the applied vibration amplitudes. The proposed method is capable of quantitative demodulation of low-frequency vibrations with a cost-effective system configuration and high computation efficiency, showing potential for commercial applications of distributed seismic or hydroacoustic wave acquisition.

In utero Exposure to Anesthetics Alters Neuronal Migration Pattern in Developing Cerebral Cortex and Causes Postnatal Behavioral Deficits in Rats.

During fetal development, cerebral cortical neurons are generated in the proliferative zone along the ventricles and then migrate to their final positions. To examine the impact of in utero exposure to anesthetics on neuronal migration, we injected pregnant rats with bromodeoxyuridine to label fetal neurons generated at embryonic Day (E) 17 and then randomized these rats to 9 different groups receiving 3 different means of anesthesia (oxygen/control, propofol, isoflurane) for 3 exposure durations (20, 50, 120 min). Histological analysis of brains from 54 pups revealed that significant number of neurons in anesthetized animals failed to acquire their correct cortical position and remained dispersed within inappropriate cortical layers and/or adjacent white matter. Behavioral testing of 86 littermates pointed to abnormalities that correspond to the aberrations in the brain areas that are specifically developing during the E17. In the second set of experiments, fetal brains exposed to isoflurane at E16 had diminished expression of the reelin and glutamic acid decarboxylase 67, proteins critical for neuronal migration. Together, these results call for cautious use of anesthetics during the neuronal migration period in pregnancy and more comprehensive investigation of neurodevelopmental consequences for the fetus and possible consequences later in life.

Magneto-optical imaging feature extraction of micro-gap weld joint under nonuniform magnetic field excitation.

To reduce the effect of the nonuniformity of magnetic field excitation on micro-gap weld joint magneto-optical (MO) imaging, a new experimental system based on the Faraday MO effect to detect micro-gap welds (gap width less than 0.1 mm) under nonuniform magnetic field excitation was developed. Horseshoe permanent magnets were used to magnetize the weldment and establish a nonuniform magnetic field at the welding joint. MO images of the micro-gap weld joint were captured using an MO sensor under nonuniform magnetic field excitation. After analyzing the distribution characteristics of the magnetic induction intensity in the weld joint area, a characterization method for the weld zone slope was proposed. The weld zone slope could accurately determine the MO imaging effects under the nonuniform magnetic field. A model based on an error backpropagation (BP) neural network was used to predict the offset of the weld joint center at each moment, and the results performed by BP were utilized to optimize the measured value of the weld joint center. Experimental results show that it can accurately extract the position of micro-gap welds under nonuniform magnetic field excitation.

Intraprocedural predictors of post-stent retriever thrombectomy subarachnoid hemorrhage in middle cerebral artery stroke.

BACKGROUND: Stent retriever thrombectomy (SRT) in acute thromboembolic stroke can result in post-thrombectomy subarachnoid hemorrhage (PTSAH). Intraprocedural findings associated with PTSAH are not well defined. OBJECTIVE: To identify angiographic findings and procedural factors during SRT that are associated with PTSAH. MATERIALS AND METHODS: This was a retrospective, observational cohort study of consecutive patients with middle cerebral artery (MCA) acute ischemic stroke treated with SRT. Inclusion criteria were: (1) age ≥18 years; (2) thromboembolic occlusion of the MCA; (3) at least one stent retriever pass beginning in an M2 branch; (4) postprocedural CT or MRI scan within 24 hours; (5) non-enhanced CT Alberta Stroke Program Early CT Score >5. Exclusion criteria included multi-territory stroke before SRT. RESULTS: Eighty-five patients were enrolled; eight patients had PTSAH (group 1) and 77 did not (group 2). Baseline demographic and clinical characteristics were comparable between the two groups. In group 1, a significantly greater proportion of patients had more than two stent retriever passes (62.5% vs 18.2%, P=0.01), a stent retriever positioned ≥2 cm along an M2 branch (100% vs 30.2%, P=0.002), and the presence of severe iatrogenic vasospasm before SRT pass (37.5% vs 5.2%, P=0.02). One patient with PTSAH and associated mass effect deteriorated clinically. CONCLUSIONS: An increased number of stent retriever passes, distal device positioning, and presence of severe vasospasm were associated with PTSAH. Neurological deterioration with PTSAH can occur.

Modeling for detecting weld defects based on magneto-optical imaging.

A magneto-optical (MO) imaging nondestructive testing (NDT) method for ferromagnetic weldments has been proposed. The mechanism of MO imaging was analyzed by the Faraday MO effect, magnetic domain theory, and magnetic hysteresis loops. Then, the relation between MO images and their corresponding excitation voltages was investigated. To explain the MO imaging system, magnetic domain distribution models of various welding states were established. These models are excited by two kinds of magnetic fields. One is the external magnetic field (Hex), and the other is a weldment remanence field (Mr) after Hex is removed. Relations of magnetic field excitation voltages, thickness of the spacer plate, and the corresponding MO images were also researched, which indicates the proposed NDT method can be used to detect incomplete penetration defect. Then, an experiment that uses MO imaging to detect the defects of high-strength steel (HSS) weldment was performed. Experimental results proved this method can detect crack, sag, and incomplete penetration of weldment effectively. Finally, a series of welded joint MO images of the HSS weldment were captured, which are used as the input data of the defect classification model established by using principal component analysis and an error backpropagation neural network, and the accuracy of this classification model can achieve 92.8%.

An 11-year retrospective review of venlafaxine ingestion in children from the California Poison Control System.

Venlafaxine is commonly used in the United States for approved and non-Food and Drug Administration-approved indications in adults. It is used off-label to treat children for psychiatric diagnoses. The aim of the study was to describe venlafaxine toxicities in children and to identify the venlafaxine dose per weight that correlates with toxicities. An 11-year retrospective study of venlafaxine ingestion in children was performed using the California Poison Control System (CPCS) database. Data was extracted from phone calls received by CPCS clinicians and follow-up phone calls made to assess the patient's progress in a health-care setting. Inclusion criteria were venlafaxine ingestion cases reported to CPCS between January 2001 and December 2011, children aged 20 years and under, venlafaxine as the only ingested substance, managed in a health-care facility, and followed to a known outcome. Two hundred sixty-two cases met the study criteria. Common presentations included gastrointestinal (14.9%), altered mental status (13.7%), and tachycardia (13.4%). The majority of the cases resulted in no effect (51.5%) or minor effect (19.9%). The average estimated dose per weight was 18.3 mg/kg in all patients and 64.5 mg/kg in those experiencing moderate-to-severe adverse effects. Seizures occurred in only 4 of the 262 cases at doses ranging from 1500 to 7500 mg. Although the estimated dose per weight exceeded 10 mg/kg for the majority of the cases, only 12 cases resulted in moderate or severe outcomes. The majority of venlafaxine ingestion cases in children resulted in either no clinical effects or minor clinical effects.

Lanosterol reverses protein aggregation in cataracts.

The human lens is comprised largely of crystallin proteins assembled into a highly ordered, interactive macro-structure essential for lens transparency and refractive index. Any disruption of intra- or inter-protein interactions will alter this delicate structure, exposing hydrophobic surfaces, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness worldwide, affecting tens of millions of people, and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins both prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations (W581R and G588S) in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type, but not mutant, LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. We further show that lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

A phase I-II evaluation of veliparib (NSC #737664), topotecan, and filgrastim or pegfilgrastim in the treatment of persistent or recurrent carcinoma of the uterine cervix: an NRG Oncology/Gynecologic Oncology Group study.

PURPOSE: The aim of this study was to evaluate the tolerability and efficacy of poly(ADP-ribose) polymerase (PARP) inhibition by veliparib during cytotoxic topotecan administration with filgrastim or pegfilgrastim neutrophil support in women with persistent or recurrent uterine cervix cancer. EXPERIMENTAL DESIGN: This phase I-II trial examined twice-daily oral veliparib (10 mg) given during once-daily intravenous topotecan (0.6 mg/m²) on days 1 to 5 of each treatment cycle. Cycles were repeated every 21 days until disease progression or until toxicity prohibited further therapy. Toxicity and objective response rate were primary endpoints. RESULTS: Twenty-seven women were enrolled. Frequently reported grade 3 or higher treatment-related toxicities were anemia (59%), thrombocytopenia (44%), leukopenia (22%), and neutropenia (19%). There were 2 partial responses (7% [90% confidence interval, 1%-22%]). Four patients had a disease progression date more than 6 months after the start of veliparib-topotecan therapy. Patients with low immunohistochemical expression (0-1+) of PARP-1 in their primary uterine cervix cancer were more likely to have a longer progression-free interval (hazard ratio, 0.25; P = 0.02) and survival (hazard ratio, 0.12; P = 0.005) after veliparib-topotecan therapy. CONCLUSIONS: Clinical activity of a veliparib-topotecan combination was minimal in women with persistent or recurrent uterine cervix cancer. Women whose uterine cervix cancers express PARP-1 at low levels may benefit preferentially from PARP inhibitors combined with cytotoxic therapies, suggesting further study of PARP expression as an integral triage biomarker.

A survey of public attitudes towards barking dogs in New Zealand.

AIMS: To investigate public attitudes towards barking dogs in New Zealand in order to quantify the extent to which people perceive barking dogs to be a problem, to compare tolerance of barking with that of other common suburban noises, to assess the level of public understanding about the function of barking, to determine risk factors for intolerance of barking and to assess knowledge of possible strategies for the investigation and management of problem barking. METHODS: A 12-page questionnaire was sent to 2,000 people throughout New Zealand randomly selected from the electoral roll. Risk factors for being bothered by barking were examined using logistic regression analysis. RESULTS: A total of 1,750 questionnaires were successfully delivered; of these, 727 (42%) were returned. Among respondents, 356/727 (49.0%) indicated that frequent barking during the day would bother them while 545/727 (75.0%) would be bothered by barking at night. Barking and howling were ranked above other suburban noises as a cause of annoyance. Risk factors for being bothered by daytime barking were not being home during the day, not owning a dog, and considering a dog bite to be a serious health risk. Risk factors for being bothered by night-time barking were not being home during the day, marital status, considering dog bites to pose a serious health risk, and having been frightened by a dog. Overall, 510/699 (73%) respondents understood that barking was a form of communication. Action likely to be taken by 666 respondents hearing frequent barking included notifying and offering to help the owner (119; 17.8%), complaining to the owner (127; 19.1%) or the authorities (121; 18.2%), or doing nothing (299; 48%). Possible responses by 211 dog owners if they had a barking dog included seeking help from dog trainers (59; 28%) or behaviourists (54; 26%), buying an anti-barking device (33; 15%) or getting rid of the dog (20; 10%). CONCLUSIONS: Barking was considered to be potentially disturbing by respondents to this survey. Attitudes towards barking were most influenced by age, dog ownership, past experience with dogs and attitude towards dog bites. Public understanding of the possible reasons for barking and appropriate methods of managing the behaviour when it becomes a problem could be improved by better education and the provision of information through veterinary clinics and social media.

Delayed onset of anterior spinal artery syndrome after repair of aortic coarctation.

STUDY DESIGN: A case report. OBJECTIVE: We report a case of delayed anterior spinal artery syndrome after repair of aortic coarctation in which the symptoms did not appear until 6 months after surgery. SUMMARY OF BACKGROUND DATA: Residual dilatation of the anterior spinal artery after surgery can mimic a dilated intraspinal vein, which could lead to the erroneous diagnosis of spinal arteriovenous malformation as the cause for anterior spinal artery syndrome. METHODS: A 40-year-old man with a history of hypertension underwent surgical bypass of the left subclavian artery to descending thoracic aorta to treat coarctation of the thoracic aorta and had an uncomplicated postoperative course. Six months later, he developed numbness and weakness in his hands. Magnetic resonance image showed abnormal signal within the cervicothoracic spinal cord and prominent flow voids within the ventral spinal canal. Spinal digital subtraction angiography revealed slow flow in a dilated intraspinal vessel. Given the history of aortic coarctation repair, the possibility that this represented a residually dilated anterior spinal artery rather than an arteriovenous malformation was considered and confirmed on magnetic resonance imaging. RESULTS: In our patient, institution of an anticoagulation medication regime resulted in rapid improvement of neurological symptoms, underscoring the importance of the awareness of this phenomenon. CONCLUSION: Delayed anterior spinal artery syndrome after aortic coarctation repair because of anterior spinal artery thrombosis can manifest even 6 months postoperatively. Careful analysis of pre- and postoperative cross-sectional imaging should provide the correct diagnosis. Spinal digital subtraction angiography is probably unnecessary and must be interpreted with caution.

Optimized half-wave voltage and insertion loss in a strip-loaded waveguide electro-optic polymer modulator.

A strip-loaded waveguide, electro-optic modulator was designed and analyzed in terms of single mode conditions, optical loss due to the metal electrodes, modulation efficiency, and mode size. Two designs were compared: Design 1 optimized the half-wave voltage (V(π)=1.1 V) with a nearly symmetric waveguide by maximizing modulation efficiency and minimizing the overall thickness of the waveguide; Design 2 optimized the insertion loss by reducing coupling loss by 4.6 dB via a strongly asymmetric waveguide that maximizes the overall mode size to most efficiently overlap with a single mode fiber. Design 2 also has a favorable half-wave voltage (V(π)=1.75 V). Some general guidelines in the selection of cladding layers in a detailed design of a poled-polymer electro-optic modulator incorporating a strip-loaded waveguide structure are suggested.

Intraoperative magnetic resonance imaging and neuronavigation for transoral approaches to upper cervical pathology.

BACKGROUND: The transoral transpharyngeal surgical approach is a recognized technique for management of ventral lesions at the clivus and upper cervical spine. This report examines the use of neuronavigation and intraoperative magnetic resonance imaging as surgical adjuncts for lesions in this region. METHODS: A retrospective review of patients undergoing transoral transpharyngeal surgery in the intraoperative magnetic resonance imaging (iMRI) unit from 1997 to present was performed. Preoperative demographic data, clinical history, physical examination, and imaging studies were reviewed. Data were collected on surgical approach, pathology, postoperative management, and adverse events. RESULTS: Twenty patients underwent resection of ventral lesions at the craniovertebral junction through a transoral approach in the iMRI suite. Mean age at time of surgery was 50 years. A variety of pathologies were identified including neoplasms (n=7), congenital anomalies (n=7), and degenerative disease (n=6). Intraoperative imaging and neuronavigation allowed for tailoring of the surgical approach in each of our patients: 11 patients underwent transoral surgery without a palatal split or mandibulotomy; 9 patients underwent a palatal split and of these, 5 required a mandibulotomy. Interdissection images allowed for immediate confirmation of gross total resection in all cases. Postoperatively, patients were managed in the intensive care unit for an average of 7 days. Ninety-two percent of patients had neurological improvement at a mean of 1.8 years of follow-up (range 0.4-6 years). Two patients died from tumor progression and one died from renal failure. CONCLUSIONS: Intraoperative MRI and neuronavigation are valuable adjuncts that allow selective surgical exposure and confirmation of surgical objectives within the narrow surgical corridor provided by a transoral approach to the craniovertebral junction.

Preoperative embolization of the inferior petrosal sinus in surgery for glomus jugulare tumors.

OBJECTIVE: To compare the outcomes of surgery for glomus tumors involving the jugular foramen with and without preoperative venous embolization of the inferior petrosal sinus (IPS). STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Twenty-four patients with paragangliomas involving the jugular foramen treated between 1995 and 2008. INTERVENTION: All patients underwent surgical resection after receiving preoperative angioembolization with or without venous embolization of the IPS. MAIN OUTCOME MEASURES: Total operative duration, estimated blood loss, intensive care unit and total hospital days, and novel postoperative lower cranial nerve deficits were recorded, and appropriate statistical analysis was conducted. RESULTS: Twenty-four patients met inclusion criteria. Fourteen of these patients underwent preoperative embolization of the IPS in addition to angioembolization. The group that did not undergo embolization of the IPS was used as the control group (n = 10). These groups were compared with regard to the above outcome measures. Blood loss and new lower cranial nerve deficits were reduced in the venous embolization group, although neither measure reached statistical significance. Tumor size correlated with increased intraoperative hypotensive events and longer total hospital stay, and these correlations were statistically significant. CONCLUSION: Preoperative embolization of the IPS is possible in many patients undergoing surgery of the jugular foramen. The addition of venous embolization to the traditional arterial embolization of glomus jugulare tumors adds little additional time or expense to the procedure and facilitates control of bleeding once the jugular bulb has been opened.

Phase II evaluation of sorafenib in advanced and metastatic squamous cell carcinoma of the head and neck: Southwest Oncology Group Study S0420.

PURPOSE: We conducted a phase II trial to evaluate the efficacy and safety of single-agent sorafenib in chemotherapy-naïve patients with metastatic or recurrent squamous cell carcinoma of the head and neck (SCCHN). The primary end point was response probability (ie, confirmed complete and partial response [PR]). PATIENTS AND METHODS: Chemotherapy-naïve patients with metastatic, persistent, or recurrent SCCHN who received one induction or fewer or received an adjuvant chemotherapy regimen, who had adequate organ function, and who had a performance status

Characteristics of adult dog owners in New Zealand.

AIM: To investigate the characteristics of adult dog owners in New Zealand, and to identify factors that influence dog ownership. METHODS: A 12-page questionnaire comprising 48 questions was sent to 2,000 people throughout New Zealand randomly selected from the electoral roll. RESULTS: Seven hundred and twenty-seven completed questionnaires were received from 1,750 questionnaires successfully delivered, a response rate of 42%. Twenty-nine percent (211/727) of respondents currently owned dogs, and 32% (233/727) had never owned a dog; the remaining 39% (283/727) had some history of dog ownership. The level of dog ownership was influenced by the type of dwelling, region, age, marital status, presence and age of children, and type of personality. CONCLUSIONS: Dog owners in New Zealand are likely to be aged between 18 and 55 years, educated to secondary school level or above, live in a rural or suburban area, be married or in a de-facto relationship with children over the age of one year, and consider themselves to be of positive character.

A survey of adult victims of dog bites in New Zealand.

AIM: To describe the circumstances of dog bites to adults in New Zealand, in order to better understand factors associated with these bites. METHODS: A questionnaire was sent to 1,800 adults aged > or =16 years who had made claims to the Accident Compensation Corporation (ACC) in 2002 as a result of dog bites. RESULTS: Five hundred and thirty-five questionnaires were returned; 50% of respondents were male, and 30% of bites were reported to local authorities. Most injuries were to the legs or hand. More people were bitten by male dogs than female dogs. A disproportionate number of bites took place in rural areas, but the most common locations for attacks were streets/walkways, and the victim's home. Protection of territory, accidental bites, fear, and pain were considered to be the most common reasons for dogs to bite. CONCLUSION: Many victims were bitten in situations that could have been avoided.

The pulmonary artery catheter sleeve--protective or infective?

The use of sterile plastic sleeves to protect pulmonary artery catheters (PAC) may decrease infection risk. The catheter may require manipulation but contamination of the sleeve risks inoculating organisms into the patients. We sought to determine whether the sleeve remains sterile and for how long. We conducted a prospective observational study to culture the components of the PAC in a critically ill population. Upon removal we cultured 1) the PAC tip, 2) the PAC introducer exit site, 3) the PAC introducer hub and 4) a sterile irrigant solution which ran down the inside of the protective sleeve. Demographic, catheter and disease variables were also collected. There were 102 PAC episodes amounting to 3952 catheter hours with a mean duration of catheterisation of 39.1 (24.2) hours. There were 17 positive culture results, of which six were positive sleeve fluid cultures. In three of these patients the exit site was culture positive, and the same organism was isolated as within the sleeve. No patient had a positive blood culture. There was no difference between those with and without a positive sleeve culture in terms of demographic or disease variables. The protective sleeve of the pulmonary artery catheter does not remain sterile and should not be considered as a sterile barrier. We believe that manipulating the PAC within the sleeve carries the risk of inoculating the patient with pathogenic organisms. The duration of sterility remains to be determined.

Extended intracranial applications for ethylene vinyl alcohol copolymer (Onyx): mycotic and dissecting aneurysms. Technical note.

The authors describe the off-label use of Onyx for embolization of fusiform mycotic and dissecting intracranial aneurysms based on their experience with 3 patients treated at the University of Utah Hospital from 2006 through 2007. Technical success in occluding the parent artery/aneurysm was achieved in all patients. There were no complications. The authors conclude that Onyx can be used to achieve occlusion of fusiform mycotic and dissecting intracranial aneurysms in conjunction with parent artery occlusion.