An Audit of 6 years of Oral and Maxillofacial Surgical Conditions admitted for Interventional Treatment at Muhimbili National Hospital, Dar es Salaam – Tanzania

Background: The world wide pattern of OMFS conditions has been rarely reported despite its significance in the head and neck medicine; maxillofacial trauma and tumors. The main objective of this study was to audit oral and maxillofacial surgical (OMFS) conditions admitted for interventional treatment at Muhimbili National Hospital. Methods: Patients presenting to the OMFS unit with oral and maxillofacial pathological conditions between January 2003 - January 2009 were studied prospectively. Data for analysis were obtained from the daily operation list and includes age, sex, location, diagnosis of the pathological lesion, surgical procedure and date of procedure. Results: During the study period, the unit offered specialized services to 454 patients. Among them, 222 were males and 232 females. The mean age of the patients was 31.7 and the range was 79 years. Patient aged 21-30 years were mostly affected. Of the pathological lesions attended, benign tumors were the most common 255(56.2%) followed by fractures 58(12.8%), cysts 46(10.1%), malignant tumors 36(7.9%) and chronic infections 17(3.7%). Of the 255 cases of benign tumors 155(60.8%) were located on the mandible and 64 (25.1%) on the maxilla. Malignant tumors were 36 cases in which 11(30.6%) were located on the mandible. Maxillofacial fractures accounted 58 cases in which 31(53.4%) cases were located on the mandible. Cysts were 46 cases of which 17(37%) were located on the floor of the mouth, 10(21.7%) on the mandible and 7(15.2%) on the maxilla. Tumor excision was the commonest procedure performed 119(26.2%), followed by Tumor excision + reconstruction 89(19.6%), ORIF+IMF 51(11.2%), Fistulectomy 45(9.9%), Tumor enucleation 45(9.9%), Wide surgical excision 27(5.9%), Sinusectomy 16(3.5%) and Sequestrectomy 15(3.3%). Conclusion: There is a significant burden of OMFS conditions attended at MNH. We suggest that the government enhance the state of medical infrastructure in the local hospitals in terms of manpower and facilities for the diagnosis and treatment of simpler OMFS disease as well as timely referral on to regional center for the more complex issues. This will reduce the burden of OMF conditions experienced by this hospital and improve OMF services country wide

Segregation and precipitation of Er in Ge

Although Er-doped Genanomaterials are attractive for photonic applications, very little is known about the basic properties of Er in Ge. Here, the authors study the annealing behavior of Geimplanted with keV Er ions to doses resulting in ≲1at.% of Er. Large redistribution of Er, with segregation at the amorphous/crystalline interface, starts at ≳500°C, while lower temperatures are required for material recrystallization. However, even at 400°C, Er forms precipitates. The concentration of Er trapped in the bulk after recrystallization decreases with increasing temperature but is independent of the initial bulk Er concentration for the range of ion doses studied here.Work at the ANU was supported by the ARC

Bacteriological Quality of Fresh Vegetables and Peeled Sugar-Cane Obtained from Selected Markets in Zaria, Nigeria

Fresh vegetables and peeled sugar-cane serves as an essential component of a healthy diet, but despite their benefit they are prompt to bacterial contamination. The bacteriological quality of four types of fresh vegetables and peeled sugar-cane obtained from selected markets in Zaria, Nigeria was determined using standard microbiological method. The fresh vegetables, peeled sugar-cane, water and hand-swab samples were collected from four different locations namely; Samaru, Sabon-gari, Tudun-wada and Zaria-city. The total bacteria plate counts ranged from 3.3 x 106 cfu/g to 1.6 x 107 cfu/g with Tudu-wada having the highest bacteria load in lettuce. The coliform count of fresh vegetables and peeled sugar-cane varies from 1.3 x 104 to 8.6 x 105 cfu/g in the entire markets with Tudu-wada having the highest value in cucumber, the counts were obviously above specified Standard of 105 cfu/g and  103 cfu/g (ICMSF, 1978). Pathogenic bacteria isolated include; Citrobacter fruendii, Escherichia coli, Enterobacter spp., Klebsiella. spp., Shigella spp., Serratia spp., Cronobacter sakazaki, Staphylococcus aureus, Pseudomonas spp., and others Staphylococci spp.. This study showed that, fresh vegetables and peeled sugar-cane are contaminated with pathogenic bacteria making them unsafe for human consumption; hence fresh produce should be pre- treated thoroughly, so as to reduce the risk of food- borne outbreaks. Keywords: Pathogenic bacteria · Bacteriological quality, Microbiological method, Coliform counts and food- borne outbreaks. DOI: 10.7176/JNSR/12-8-02 Publication date: April 30th 202

Correlated Markov Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on $\Z^d$ performed by a particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in $\Z^d$ for random updates of the coin states of the following form. The random sequences of unitary updates are given by a site dependent function of a Markov chain in time, with the following properties: on each site, they share the same stationnary Markovian distribution and, for each fixed time, they form a deterministic periodic pattern on the lattice. We prove a Feynman-Kac formula to express the characteristic function of the averaged distribution over the randomness at time $n$ in terms of the nth power of an operator $M$. By analyzing the spectrum of $M$, we show that this distribution posesses a drift proportional to the time and its centered counterpart displays a diffusive behavior with a diffusion matrix we compute. Moderate and large deviations principles are also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. An example of random updates for which the analysis of the distribution can be performed without averaging is worked out. The random distribution displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix whose law we compute. We complete the picture by presenting an uncorrelated example.Comment: 37 pages. arXiv admin note: substantial text overlap with arXiv:1010.400

Ion-beam-produced structural defects in ZnO

We study the evolution of lattice defects in single-crystal ZnO bombarded with 60-keV Si-28 and 300-keV Au-197 ions at 77 and 300 K. To characterize ion-beam-produced structural defects, we use a combination of Rutherford backscattering/channeling (RBS/C) spectrometry, cross-sectional transmission electron microscopy (XTEM), x-ray photoelectron spectroscopy, and atomic force microscopy. Results show that ZnO exhibits strong dynamic annealing, and even high-dose bombardment with heavy (Au-197) ions at 77 K does not render ZnO amorphous. However, a crystalline-to-amorphous phase transition can be induced by irradiation with relatively light Si-28 ions. In this latter case, amorphization is attributed to strong chemical effects of Si atoms implanted into the ZnO lattice, resulting in the stabilization of an amorphous phase. High-dose heavy-ion bombardment also results in a strong stoichiometric imbalance (loss of O) in the near-surface region. A variation in irradiation temperature from 77 up to 300 K has a minor effect on the damage buildup behavior in ZnO bombarded with Au ions. Data analysis also shows that a variation in the density of collision cascades by increasing ion mass from Si-28 up to Au-197 has a negligible effect on the damage buildup behavior. For both light- (Si-28) and heavy- (Au-197) ion bombardment regimes, XTEM reveals that ion irradiation produces energetically favorable planar defects which are parallel to the basal plane of the wurtzite structure of ZnO. Interestingly, our RBS/C study also reveals the formation of a middle defect peak between the surface and bulk peaks of disorder in Au-implanted ZnO, but not in Si-bombarded samples. The formation of this middle peak, most likely to be related to complex defect agglomeration processes, is rather unexpected and, to our knowledge, has not been observed in any other material. Physical mechanisms of defect formation in ZnO under ion bombardment are discussed based on these experimental findings

Reversible dilated cardiomyopathy caused by hypothyroidism

The association between lack of thyroid hormones and cardiac dysfunction has been well described. We report two new cases of patients with dilated cardiomyopathy (DCM), revealing a periphery hypothyroidism and for whom cardiac function significantly improved after L thyroxin substitutive treatment. Our cases highlight the necessity to perform thyroid function testing to investigate the etiology of non ischemic DCM

Synthesis and Characterization of Bimodal Nanoporous Cu Foams: Working Towards Inertial Fusion Energy

For the National Ignition Facility, at the Lawrence Livermore National Laboratory, nanoporous structures play a crucial role in the development of targets for high energy density experiments. Here we present a new bottom-up synthesis technique termed filter-casting for the creation of bimodal macro/nanoporous Cu structures. Homogeneous nanoporous monoliths can be synthesized using Cu nanoparticles and bimodal porosities can be achieved using sacrificial polystyrene spheres as a template. Control over the structure and composition is critical for target manufacturing. The measured densities of the Cu foam range between 1070-3390 mg/cm{sup 3}. Filter-casting is a powerful new method for directly synthesizing large nanoporous monoliths with predetermined composition, pore size, and pore structure

Random Time-Dependent Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on the lattice $\Z^d$ performed by a quantum particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in $\Z^d$ when the sequence of unitary updates is given by an i.i.d. sequence of random matrices. When averaged over the randomness, this distribution is shown to display a drift proportional to the time and its centered counterpart is shown to display a diffusive behavior with a diffusion matrix we compute. A moderate deviation principle is also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. A generalization to unitary updates distributed according to a Markov process is also provided. An example of i.i.d. random updates for which the analysis of the distribution can be performed without averaging is worked out. The distribution also displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix whose law we compute. A large deviation principle is shown to hold for this example. We finally show that, in general, the expectation of the random diffusion matrix equals the diffusion matrix of the averaged distribution.Comment: Typos and minor errors corrected. To appear In Communications in Mathematical Physic

Nanoengineering mechanically robust aerogels via control of foam morphology

Potential of aerogels for technological applications is often limited by their poor mechanical properties. Here, we demonstrate that alumina aerogel monoliths with excellent mechanical properties can be made by controlling the crystallographic phase, shape, and size of nanoligaments. In particular, we show that thermal processing of aerogels with a morphology of interconnected nanoleaflets causes dehydration and associated curling of the nanoleaflets, resulting in a dramatic improvement of mechanical properties. This study shows an effective way to control mechanical properties of the nanoporous solids that can be synthesized with ligaments having a quasi-two-dimensional shape, such as platelets, ribbons, or leaflets.Work at the ANU was supported by the ARC

Nanoporous gold as a highly active substrate for surface-enhanced Raman scattering spectroscopy

Colloidal solutions of metal nanoparticles are currently among most studied substrates for sensors based on surface-enhanced Raman scattering (SERS). However, such substrates often suffer from not being cost-effective, reusable, or stable. Here, we develop nanoporous Au as a highly active, tunable, a.ordable, stable, bio-compatible, and reusable SERS substrate. Nanoporous Au is prepared by a facile process of free corrosion of AgAu alloys followed by annealing. Results show that nanofoams with average pore sizes of {approx} 250 nm exhibit the largest SERS signal for 632.8 nm excitation. This is attributed to the electromagnetic SERS enhancement mechanism with additional field localization within pores