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Baseline holder (BLH) circuits are used widely to stabilize the analog output of application-specific integrated circuits (ASICs) for high-count-rate applications. The careful design of BLH circuits is vital to the overall stability of the analog-signal-processing chain in ASICs. Recently, we observed self-triggered fluctuations in an ASIC in which the shaping circuits have a BLH circuit in the feedback loop. In fact, further investigations showed that methods of enhancing small-signal stabilities cause an even worse situation. To resolve this problem, we used large-signal analyses to study the circuit's stability. We found that a relatively small gain for the error amplifier and a small current in the non-linear stage of the BLH are required to enhance stability in large-signal analysis, which will compromise the properties of the BLH. These findings were verified by SPICE simulations. In this paper, we present our detailed analysis of the BLH circuits, and propose an improved version of them that have only minimal self-triggered fluctuations. We summarize the design considerations both for the stability and the properties of the BLH circuits.

A new low-power application-specific integrated circuit (ASIC) for Cadmium Zinc Telluride (CZT) detectors for single-photon emission computed tomography (SPECT) application is being developed at BNL. As the first step, a 32-channel prototype ASIC was designed and tested recently. Each channel has a preamplifier followed by CR-RC3 shaping circuits and three independent energy bins with comparators and 16-bit counters. The ASIC was fabricated with TSMC 0.35-μm complementary metal-oxide-semiconductor (CMOS) process and tested in laboratories. The power consumption is around 1 mW/ch with a 2.5-V supply. With a gain of 400 mV/fC and the peaking time of 500 ns, the equivalent noise charge (ENC) of 360 e- has been measured in room temperature while the crosstalk rate is less than 0.3%. The 10-bit DACs for global thresholds have an integral nonlinearity (INL) less than 0.56% and differential nonlinearity (DNL) less than 0.33%. In the presentation, we will report the detailed test results with this ASIC.

The use of low-cost sensors, with open-source code, facilitates greater spatial resolution and flexibility of environmental monitoring, thus generating more information and overcoming limitations of traditional commercial sensors. Measurement of water turbidity using submerged sensors can be problematic in that rapid biofouling requires frequent site visits to remove, clean, calibrate and replace the sensor. We therefore designed an automated system using low-cost commercially-available sensors that pumps water from the stream, samples it for turbidity and purges remaining water, leaving the turbidity sensor dry between measurements, thus greatly reducing the biofouling problem and minimizing operation costs. Our station was able to estimate suspended sediment concentrations between 0 and 6 g/L with a root mean square error (RMSE) around 5 % of the total range, which meets typical research and operational study requirements. The results showed that the monitoring station is capable of monitoring water level and turbidity for long periods without the need of cleaning the turbidity sensor, due to its purge function. We demonstrated that spatially intense measurement of turbidity within catchments and drainage networks can be achieved at a relatively low cost, which allows a better understanding of the main sources of suspended sediments and their spatial and temporal variability., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Quantifying pollutant removal by stormwater wetlands requires intensive sampling which is cost-prohibitive for authorities responsible for a large number of wetlands. Wetland managers require simple indicators that provide a practical means of estimating performance and prioritising maintenance works across their asset base. We therefore aimed to develop vegetation cover and metrics derived from monitoring water level, as simple indicators of likely nutrient pollutant removal from stormwater wetlands. Over a two-year period, we measured vegetation cover and water levels at 17 wetlands and used both to predict nitrogen (N) and phosphorus (P) removal. Vegetation cover explained 48 % of variation in total nitrogen (TN) removal; with a linear relationship suggesting an approximate 9 % loss in TN removal per 10 % decrease in vegetation cover. Vegetation cover is therefore a useful indicator of TN removal. Further development of remotely-sensed data on vegetation configuration, species and condition will likely improve the accuracy of TN removal estimates. Total phosphorus (TP) removal was not predicted by vegetation cover, but was weakly related to the median water level which explained 25 % of variation TP removal. Despite weak prediction of TP removal, metrics derived from water level sensors identified faults such as excessive inflow and inefficient outflow, which in combination explained 50 % of the variation in the median water level. Monitoring water levels therefore has the potential to detect faults prior to loss of vegetation cover and therefore TN removal, as well as inform the corrective action required., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Stormwater infiltration basins have been used extensively around the world to restore urban hydrology towards more natural flow and water quality regimes. There is, however, significant uncertainty in the fate of infiltrated water and accompanying contaminants that depends on multiple factors including media characteristics, interactions with downslope vegetation, legacy contaminants, and presence of underground infrastructure. Understanding the influence of such factors is thus central to the design and siting of infiltration basins. An extensive field program was established to collect monthly data on ground water quality, including nutrients and major ion concentrations, in a bore network downstream of a stormwater infiltration basin in Victoria, Australia. The groundwater samples were analysed for temperature, pH, EC, turbidity, major ions (Na + , Ca 2+ , K + , Mg 2+ , Cl - , SO 4 2- , NO 3 - , CO 3 2- , HCO 3 - ), NOx and heavy metals. The collected data were used to understand the origin and fate of water and solutes in the subsurface and their interactions with the soil matrix. The results revealed that Ca-HCO 3 , Na-Cl water types predominate in the study area, grouped in 3 clusters; shallow fresh groundwater in the vicinity of the basin (near basin), deep saline groundwater further downstream of the basin (near-stream) and a mid-section where rock-water interaction (Na-HCO 3 water) through cation exchange control the chemistry of groundwater. The results also suggest that as the water moves downstream of the basin, it experiences significant evapotranspiration and concentration due to the presence of deep-rooted vegetation. The results suggest that while infiltration basins can remove infiltrated contaminants, the infiltrated stormwater can mobilise legacy contaminants such as nitrate. Overall, the efficacy of infiltration basins in urban regions depends substantially on the downstream vegetation, urban underground infrastructure and the presence of legacy contaminants in the soils. These all need to be considered in the design of stormwater infiltration basins., (© 2023. The Author(s).)

We performed a gradual low-temperature annealing up to 360 K on a CdZnTeSe radiation detector equipped with gold and indium electrodes under bias at both polarities. We observed significant changes in the detector's resistance and space-charge accumulation. This could potentially lead to the control and improvement of the electronic properties of the detector because the changes are accompanied with the reduction in the bulk dark current and surface leakage current. In this article, we present the results of a detailed study of the internal electric field and conductivity changes in CdZnTeSe detector for various annealing steps under bias taking into account different polarities during annealing and subsequent characterization. We observed that low-temperature annealing results in an increase in the barrier height at the contacts that, in general, reduces the dark current and decreases the positive space charge present in the sample compared to the pre-annealed condition.

Both material quality and detector performance have been steadily improving over the past few years for the leading room temperature radiation detector material cadmium-zinc-telluride (CdZnTe). However, although tremendous progress being made, CdZnTe still suffers from high concentrations of performance-limiting defects, such as Te inclusions, networks of sub-grain boundaries and compositional inhomogeneity due to the higher segregation coefficient of Zn. Adding as low as 2% (atomic) Se into CdZnTe matrix was found to successfully mitigate many performance-limiting defects and provide improved compositional homogeneity. Here we report record-high performance of Virtual Frisch Grid (VFG) detector fabricated from as-grown Cd 0.9 Zn 0.1 Te 0.98 Se 0.02 ingot grown by the Traveling Heater Method (THM). Benefiting from superior material quality, we achieved superb energy resolution of 0.77% at 662 keV (as-measured without charge-loss correction algorithms) registered at room temperature. The absence of residual thermal stress in the detector was revealed from white beam X-ray topographic images, which was also confirmed by Infra-Red (IR) transmission imaging under cross polarizers. Furthermore, neither sub-grain boundaries nor their networks were observed from the X-ray topographic image. However, large concentrations of extrinsic impurities were revealed in as-grown materials, suggesting a high likelihood for further reduction in the energy resolution after improved purification of the starting material.

We studied the spectral dependence of the Vickers microhardness HV0.025 of CdZnTe and CdZnTeSe samples upon illumination and found out that it increases over the entire applied spectral range of 1540-750 nm. We also found out that the photoconductivity and microhardness are correlated. We observed changes in the correlation diagram (change of slope and an abrupt change of HV0.025 at several wavelengths of the illuminating light). Based on measurements of the relative changes of the space charge upon illumination using the Pockels effect, we suggest that the observed spectral dependence of positive photoplastic effect in CdZnTe and CdZnTeSe can be explained by the trapping of photoinduced electrons and holes, which affects the motion of the partial dislocations. The underlying physical explanation relies on the assumption that reconstructed bonds break before dislocation glide.

This paper describes a new method for direct measurement and evaluation of the inhomogeneous electrostatic vector field with translational symmetry in electro-optic materials exhibiting the Pockels effect. It is based on the evaluation of maximum transmittance of low intensity light passing through a sample under a voltage bias. Here, the sample is located between rotating crossed polarizers, and camera images are obtained at each point to determine the electric field. The evaluation procedure is demonstrated using data acquired on a CdZnTeSe quasi-hemispheric semiconductor gamma-ray detector. In addition to CdTe-related compounds, the method can be used for various other materials showing [Formula: see text] symmetry such as GaAs, CdTe, GaP, 3C-SiC, and ZnS. Furthermore, it can be generalized to other crystalline materials showing the Pockels effect. The method can be used to probe the space charge and the electric field in several kinds of electronic components and devices, as well as provide useful data on the role of defects, contact configurations and other surface and bulk inhomogeneities in the material that can affect the distribution of the internal electric field.

Background: Asthmatics are at increased cardiovascular disease risk, which has been linked to beta2(β 2 )-agonist use. Inhalation of β 2 -agonists increases sympathetic nerve activity (SNA) in healthy individuals, however the systemic impact of salbutamol in asthmatics using β 2 -agonists regularly is unknown., Objectives: This study compared the systemic vascular responses to a clinical dose of salbutamol (Phase I) and following an acute increase in SNA (Phase II) in asthmatics and controls., Methods: Fourteen controls and 14 asthmatics were recruited for Phase I. On separate days, flow-mediated dilation (FMD) and peripheral arterial stiffness (pPWV) were evaluated at baseline and following either 400 μg inhaled salbutamol or a placebo inhaler. For Phase II, heart rate, blood pressure, vascular conductance, pPWV, and central (c)PWV were evaluated in response to a large increase in SNA brought on by cold-water hand immersion (i.e. cold-pressor test) or body-temperature water hand immersion (i.e. control) in 10 controls and 10 asthmatics., Results: Following salbutamol, asthmatics demonstrated reduced FMD (-3.0%, p < 0.05) and increased pPWV (+0.7 m/s, p < 0.05); however, salbutamol had no effect in controls. The cold-pressor test resulted in similar increases in blood pressure, vascular flow rates and conductance, pPWV, and cPWV in both asthmatics and controls, suggesting similar neurovascular transduction in asthmatics and controls., Conclusion: Inhaled Salbutamol leads to increased arterial stiffness and reduced FMD in asthmatics. As asthmatics and controls had similar vascular responses to an increase in SNA, these findings suggest asthmatics have heightened sympathetic responses to β 2 -agonists which may contribute to the increased cardiovascular risk in asthma., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Cadmium zinc telluride selenide (Cd 1-x Zn x Te 1-y Se y or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i.e., without cryogenic cooling). Potential applications of CZTS sensors include medical imaging, X-ray detection, and gamma-ray spectroscopy. Chemical passivation of CZTS is needed to reduce the conductivity of Te-rich surfaces, which reduces the noise and improves the device performance. In this study, we focus on the effect of surface passivation of CZTS using a 10% aqueous solution of ammonium fluoride. The effects of the chemical treatment were studied on the leakage current, charge transport measured as the electron mobility-lifetime (µτ) product, and the spectral resolution measured as the full-width at half-maximum (FWHM) of specific peaks. After passivation, the leakage current increased and began to decrease towards pre-passivation levels. The energy resolutions were recorded for eight applied voltages between -35 V and -200 V. The results showed an average of 25% improvement in the detector's energy resolution for the 59.6 keV gamma peak of Am-241. The electron µτ product was unchanged at 2 × 10 -3 cm 2 /V. These results show that ammonium fluoride is effective for chemical passivation of CZTS detectors.

X- and gamma-ray detectors have broad applications ranging from medical imaging to security, non-proliferation, high-energy physics and astrophysics. Detectors with high energy resolution, e.g. less than 1.5% resolution at 662 keV at room temperature, are critically important in most uses. The efficacy of adding selenium to the cadmium zinc telluride (CdZnTe) matrix for radiation detector applications has been studied. In this paper, the growth of a new quaternary compound Cd 0.9 Zn 0.1 Te 0.98 Se 0.02 by the Traveling Heater Method (THM) is reported. The crystals possess a very high compositional homogeneity with less extended defects, such as secondary phases and sub-grain boundary networks. Virtual Frisch-grid detectors fabricated from as-grown ingots revealed ~0.87-1.5% energy resolution for 662-keV gamma rays. The superior material quality with a very low density of defects and very high compositional homogeneity heightens the likelihood that Cd 0.9 Zn 0.1 Te 0.98 Se 0.02 will be the next generation room-temperature detector material.

Because of its ideal band gap, high density and high electron mobility-lifetime product, cadmium zinc telluride (CdZnTe or CZT) is currently the best room-temperature compound-semiconductor X- and gamma-ray detector material. However, because of its innate poor thermo-physical properties and above unity segregation coefficient for Zn, the wide spread deployment of this material in large-volume CZT detectors is still limited by the high production cost. The underlying reason for the low yield of high-quality material is that CZT suffers from three major detrimental defects: compositional inhomogeneity, high concentrations of dislocation walls/sub-grain boundary networks and high concentrations of Te inclusions/precipitates. To mitigate all these disadvantages, we report for the first time the effects of the addition of selenium to the CZT matrix. The addition of Se was found to be very effective in arresting the formation of sub-grain boundaries and its networks, significantly reducing Zn segregation, improving compositional homogeneity and resulting in much lower concentrations of Te inclusions/precipitates. Growth of the new quaternary crystal Cd 1-x Zn x Te 1-y Se y (CZTS) by the Traveling Heater Method (THM) is reported in this paper. We have demonstrated the production of much higher yield according to its compositional homogeneity, with substantially lower sub-grain boundaries and their network, and a lower concentration of Te inclusions/precipitates.

CdZnTe (CZT) has made a significant impact as a material for room-temperature nuclear-radiation detectors due to its potential impact in applications related to nonproliferation, homeland security, medical imaging, and gamma-ray telescopes. In all such applications, common metals, such as gold, platinum and indium, have been used as electrodes for fabricating the detectors. Because of the large mismatch in the thermal-expansion coefficient between the metal contacts and CZT, the contacts can undergo stress and mechanical degradation, which is the main cause for device instability over the long term. Here, we report for the first time on our use of Al-doped ZnO as the preferred electrode for such detectors. The material was selected because of its better contact properties compared to those of the metals commonly used today. Comparisons were conducted for the detector properties using different contacts, and improvements in the performances of ZnO:Al-coated detectors are described in this paper. These studies show that Al:ZnO contacts to CZT radiation detectors offer the potential of becoming a transformative replacement for the common metallic contacts due to the dramatic improvements in the performance of detectors and improved long-term stability.

A new low-power application-specific integrated circuit (ASIC) for Cadmium Zinc Telluride (CZT) detectors for single-photon emission computed tomography (SPECT) application is being developed at BNL. As the first step, a 32-channel prototype ASIC was designed and tested recently. Each channel has a preamplifier followed by CR-RC 3 shaping circuits and three independent energy bins with comparators and 16-bit counters. The ASIC was fabricated with TSMC 0.35-μm complementary metal-oxide-semiconductor (CMOS) process and tested in laboratories. The power consumption is around 1 mW/ch with a 2.5-V supply. With a gain of 400 mV/fC and the peaking time of 500 ns, the equivalent noise charge (ENC) of 360 e- has been measured in room temperature while the crosstalk rate is less than 0.3%. The 10-bit DACs for global thresholds have an integral nonlinearity (INL) less than 0.56% and differential nonlinearity (DNL) less than 0.33%. In the presentation, we will report the detailed test results with this ASIC.

We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm(3) detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays' performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

Purpose: Molecular imaging methods may identify primary prostate cancer foci and potentially guide biopsy and optimal management approaches. In this exploratory study, safety and first human imaging experience of a novel solid state endocavity transrectal gamma-imaging (TRGI) device was evaluated., Methods: Twelve patients received 5 ± 0.5 mCi In-111 capromab pendetide (ProstaScint) intravenously and the prostate of each was imaged 4 days later transrectally using an endoluminal cadmium zinc telluride (CZT)-based compact gamma camera (ProxiScan™, Hybridyne Imaging Technologies, Inc.). Immediate and 5-7-day post imaging safety assessments were performed. In those patients with a prostate cancer diagnosis (N=10), single photon emission computed tomography (SPECT-CT) and magnetic resonance imaging (MRI) of the pelvis were also acquired. Images were reviewed and sites of suspected cancer were localized by prostate quadrant by consensus of two nuclear medicine physicians. Pathology from TRUS biopsy, or surgical pathology following prostatectomy (N=3) when available, served as the gold standard., Results: There were no serious adverse events associated with TRGI. No focal signal was detected in patients without a diagnosis of prostate cancer (N=2). Of 40 quadrants evaluated in the cancer cohort (N=10), 22 contained malignancy. In 8 of these 10 patients, the most focal site of uptake on TRGI corresponded to a prostatic quadrant with biopsy-proven malignancy. In 6 cancer-containing quadrants, TRGI was positive where SPECT-CT was negative; MRI showed a detectable abnormality in only 1 of these 6 quadrants. Qualitative image review of the planar TRGI images for prostate cancer localization was severely limited in some cases by scatter artifact within the vicinity of the prostate gland arising from physiologic urine and blood pool activity from nearby structures., Conclusions: TRGI is a safe imaging method that can potentially detect radiopharmaceutical uptake of primary prostate cancer and facilitate prostatic quadrant - localization of cancer. Further investigation of this technology is warranted., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Objective: Negative pressure wound therapy (NPWT) can be delivered in continuous or noncontinuous modes, while NPWT with instillation (NPWTi) couples NPWT with automated delivery and removal of topical wound treatment solutions and suspensions. This porcine study compared granulation response of NPWTi (instillation foam dressing with saline) to NPWT (standard foam dressing) in continuous and noncontinuous modes., Methods: Full-thickness dorsal excisional wounds in pigs were treated with continuous NPWT, intermittent NPWT, dynamic (controlled variable) NPWT, and NPWTi with saline (n = 10 per group). Wound dimensions were determined from 3D images collected on days 0, 2, 5, and 7. On day 7, animals were euthanized and specimens were harvested for histopathological review., Results: Average granulation thickness was not statistically different among continuous (3.29 ± 0.33 mm), intermittent (3.03 ± 0.47 mm), and dynamic (3.40 ± 0.34 mm) NPWT wounds at day 7. Average granulation thickness of NPWTi wounds (4.75 ± 0.54 mm), however, was statistically greater (P < .05) by 44%, 57%, and 40%, respectively, than that of wounds treated with continuous, intermittent, and dynamic NPWT. Analysis of 3D images revealed a greater reduction in wound area and perimeter in NPWTi wounds compared to all NPWT wounds (P < .05). In addition, the average wound fill rate for NPWTi wounds was faster than that for continuous (40%; P < .05), intermittent (25%; P > .05), and dynamic (65%; P < .05) NPWT wounds., Conclusions: Although not confirmed in humans, these porcine data suggest that NPWTi with saline may stimulate a faster rate of wound granulation than NPWT in continuous and noncontinuous modes.

We have studied the behavior of Cd1-xZnxTe detectors in the temperature range 24-70°C. The detector count rate stability and leakage currents are presented as a function of voltage, time, and temperature. Detector polarization due to bulk and surface effects leading to a decreased leakage current was observed. At 70°C, the position of the 32 keV photopeak of 133Ba was stable with time. The peak position varies within only 3 keV, and the peak quality factor varied between 0.31 and 0.41, for a 24 h period of operation at a 60 V bias. The net count to total count ratio was also stable, with values varying between 0.56 and 0.59. The net count to total count ratio decreased from 0.78 at 25°C to 0.71 at 60°C. The conclusion is that Cd1-xZnxTe is a promising material for gamma ray detection at temperatures above room temperature.

In many instances, orthognathic surgical cases require multiple osteotomies in the maxilla and mandible to achieve the most desirable result. When the entire maxilla and mandible are freed from their relationship with the remaining craniofacial complex, accurate repositioning and adequate stabilization can present problems. These problems can be minimized by operating in the proper sequence or by staging the procedure. Staging should be considered for the more complicated cases; in any instance, the maxilla should be operated on first.

A Free-Wilson analysis of the antibacterial activity found in a variety of quinoxaline 1,4-dioxides prepared and tested in these laboratories unexpectedly predicted that potent activity should be found in the case where the heterocyclic ring system was substituted with an acetyl group in the 2 position and a hydroxymethyl group in the 3 position (2). The synthesis and antibacterial activity of this compound, which was actually isolated in the hemiketal form (3), and of several of its derivatives are reported. 1-Hydroxy-1-methyl-1,3-dihydrofuro[3,4-b]quinoxaline 4,9-dioxide (3) possesses exceptional activity in vivo against Escherichia coli, Salmonella choleraesuis, and Pasteurella multocida.

Modification of the palatal island flap used in cleft palate surgery has been used in 39 patients with large (1.5 to 3 cm in diameter) oroantral fistulas. The high success rate can be attributed to the flap's excellent blood supply, bulk, and mobility.

The adaptation of a postauricular approach for surgical exposure of the temporomandibular articulation is presented. The ease, safety, and predictability of extensive exposure have led us to use this approach exclusively for surgical intervention in this region. It has been effectively used in cases of trauma, pathologic conditions, and reconstruction involving the TMJ. In addition to the cases reported in this series, the procedure may be adapted to oblique subcondylar oestotomies and to the treatment of a variety of regional neoplastic processes and other forms of TMJ dysfunctions that may be encountered.

A one-year prospective study of mandibular fractures that included 253 consecutive patients with 422 mandibular fractures was completed at Charity Hospital, New Orleans. Nine major categories were studied. Patients with multiple mandibular fractures seemed to have a fracture pattern. Complications associated with mandibular fractures are influenced more by location of the fracture or fractures and the cause than by a few days' delay in treatment, the specific technique in treatment, or extraction of teeth associated with the fracture. Thorough knowledge of occlusion and the masticatory apparatus is paramount in successful treatment.

An overview of infection as it applies to the oral and maxillofacial region has been provided. The following conclusions are drawn: odontogenic infections are caused by microbes found in the host's oral flora; cultures of purulent material generally will yield three to six anaerobes and one aerobe, (the aerobe is usually a Streptococcus species); Gram stains of purulent material can aid in therapeutic strategies; anaerobic as well as aerobic cultures are necessary to isolate all pathogens; pathogens found in infections of bite wounds reflect the oral flora of the aggressor; early postoperative wound infections are caused by the host's own flora, whereas later infections may be caused by hospital-acquired bacteria; and hepatitis B and herpes simplex virus are occupational hazards. Recommendations have been made for antimicrobial prophylaxis and for treatment. We recognize that some of these selections may be controversial. For instance, the value of prophylactic antibiotics in orthognathic surgery is not well defined; recommendations were made only in certain instances. However, in severe penetrating maxillofacial injuries with devitalized tissue, recommendations for antibiotics were for broad and prolonged coverage. In this instance, use of antibiotics is considered therapeutic and not prophylactic. In each instance, we tried to validate the selection. Our rationale has been to choose the antibiotics most active against the likely pathogens; additionally, consideration was given to drug toxicity and adverse reactions. We regard penicillin as the preferred agent for prophylaxis and treatment of most odontogenic infections. Alternative drugs include cephalosporins, doxycycline, and clindamycin. Erythoromycin and tetracycline are considered less effective than the former agents. Finally, we believe that successful treatment of infection depends as much on changing the microenvironment of the infected tissue by debridement and drainage as on appropriate antimicrobial therapy.

Wiskott-Aldrich syndrome has been described. Other reports and studies of the syndrome have been compiled. Discussion of the incompletely understood pathogenesis and current treatment modalities are included with a differential diagnosis of related conditions. Although this syndrome is uncommon, it is not rare. The patient's susceptibility to infection and propensity to bleed makes early recognition and vigorous treatment an important and challenging task. It is hoped that this report will foster awareness of such patients and the complications involved in treatment.

Patients who have a maxilla that is retruded or hypoplastic, or both, but who have a mandible of normal position and size, will have degrees of flatness in the middle third of the face. Using systematic clinical evaluation and cephalometric skeletal analysis, a clinically recognizable facial deformity manifested by retrusion or hypoplasia, or both, of the maxilla, anterior zygoma, and infraorbital rims has been recognized. This deformity has been classified as infraorbital maxillary deficiency. The purpose of this paper is to describe an infraorbital-maxillary osteotomy for correction of this dentofacial deformity and to give a rationale for its use. The design of this osteotomy is determined by the skeletal deformity and can be classified as either low or high. The objective is to produce simultaneously a functional occlusion and facial harmony. Two of eight cases corrected by this surgical treatment are described.

A method of surgical and prosthetic rehabilitation of the severely atrophic maxillae using pocket inlay grafts and tuberoplasty is presented. At 2 1/2 years postoperatively, the denture in a patient treated in this manner remains stable with good retention and function. The principles presented may be applied in a variety of situations to achieve greater retention and stability of the maxillary denture.

A cephalometric analysis especially designed for the patient who requires maxillofacial surgery was developed to use landmarks and measurements that can be altered by common surgical procedures. Because measurements are primarily linear, they may be readily applied to prediction overlays and study cast mountings and may serve as a basis for the evaluation of posttreatment stability.

Surgical treatment of a large anterior oronasal fistula is reported. The advantages of a lateral alotomy are discussed. Functional and esthetic results and ease of closure justify the use of this approach.