Primary Injection Research Articles

Comparison of electron injection and recombination on TiO2 nanoparticles and ZnO nanorods photosensitized by phthalocyanine.

Titanium dioxide (TiO2) and zinc oxide (ZnO) semiconductors have similar band gap positions but TiO2 performs better as an anode material in dye-sensitized solar cell applications. We compared two electrodes made of TiO2 nanoparticles and ZnO nanorods sensitized by an aggregation-protected phthalocyanine derivative using ultrafast transient absorption spectroscopy. In agreement with previous studies, the primary electron injection is two times faster on TiO2, but contrary to the previous results the charge recombination is slower on ZnO. The latter could be due to morphology differences and the ability of the injected electrons to travel much further from the sensitizer cation in ZnO nanorods.

Paraffinoma induced bilateral preauricular cheek skin defects.

“Paraffinoma” is a well-recognized complication of paraffin oil injection into various body parts for an aesthetic purpose. After a variable latency phase, paraffinoma can present as a wide range of clinical symptoms. This paper is a case report of surgical excision of the paraffinoma and subsequent reconstruction of the associated skin defect on bilateral preauricular cheeks, manifesting 50 years after a primary injection.

Aqueous cytokine levels associated with severity of type 1 retinopathy of prematurity and treatment response to ranibizumab.

To determine the aqueous humor levels of cytokines in eyes with type 1 retinopathy of prematurity (ROP) before primary intravitreal injection of ranibizumab (IVR). Forty-nine infants with type 1 ROP (56 eyes of 28 infants in the threshold ROP group and 42 eyes of 21 infants in the type 1 pre-threshold ROP group) received primary IVR and 49 aqueous humor samples were obtained preoperatively. Aqueous humor samples from 15 infants (15 eyes) undergoing congenital cataract surgery were used as controls. The concentrations of 27 cytokines were measured by a multiplex bead assay. Infants with persistent, recurrent, or progressive ROP after IVR were retreated. The preoperative aqueous levels of 16 cytokines were significantly different among type 1 pre-threshold, threshold ROP, and control groups (P < 0.05). The concentrations of vascular endothelial growth factor (VEGF) (P < 0.001), interferon-γ (P < 0.001), interleukin (IL)-10 (P < 0.001), and IL-12 (P < 0.001) were the highest in the threshold ROP group, less in the type 1 pre-threshold ROP group, and the lowest in the control group. Retreatment was given to 55% of infants with ROP within a 48-week follow-up period after primary IVR. Higher VEGF (hazard ratio [HR] = 1.001, P = 0.001) and macrophage inflammatory protein-1β (HR = 1.085, P = 0.022) levels were independently correlated with ROP retreatment. Higher aqueous levels of VEGF and inflammatory cytokines were associated with more severe type 1 ROP and ROP retreatment after primary IVR.

Biomass Combustion in a 140kW Fixed Bed Boiler: a Joint Experimental and Modeling Study

Computational Fluid Dynamics (CFD) modeling and experimental campaigns have been performed to investigate the performance of a 140 kW biomass fixed-bed boiler. The most widely used modeling approaches in literature, such as those representing the biomass bed as a single or a series of interconnected perfectly stirred reactors, were shown to be unsuited and affected by large uncertainties on the model definition. Indeed, point measurements just above the fuel bed, performed in this work, have shown that, despite the small bed dimension, temperatures are strongly not uniform. In the present work, a simple and efficient method to overcome these limitations is suggested by representing the biomass bed as a porous medium with sources and sinks of chemical species and energy. In this manner the impact of the primary air injection on the resulting field is taken into account. The predictions provide a satisfactory agreement with the available measurements, even though improvements have to be made especially for better describing the kinetics.

Bayesian analysis of the break in DAMPE lepton spectra

Recently, DAMPE has released its first results on the high-energy cosmic-ray electrons and positrons (CREs) from about $25$ GeV to $4.6$ TeV, which directly detect a break at $\sim 1$ TeV. This result gives us an excellent opportunity to study the source of the CREs excess. In this work, we used the data fo proton and helium flux (from AMS-02 and CREAM), $\bar{\mathrm{p}}/\mathrm{p}$ ratio (from AMS-02), positron flux (from AMS-02) and CREs flux (from DAMPE without the peak signal point at $\sim 1.4$ TeV) to do global fitting simultaneously, which can account the influence from the propagation model, the nuclei and electron primary source injection and the secondary lepton production precisely. For extra source to interpret the excess in lepton spectrum, we consider two separate scenarios (pulsar and dark matter annihilation via leptonic channels) to construct the bump ($\gtrsim 100$ GeV) and the break at $\sim 1$ TeV. The result shows: (i) in pulsar scenario, the spectral index of the injection should be $\nu_{\mathrm{psr}} \sim 0.65$ and the cut-off should be $R_{c} \sim 650$ GV; (ii) in dark matter scenario, the dark matter particle's mass is $m_{\chi} \sim 1208$ GeV and the cross section is $\langle \sigma v \rangle \sim 1.48 \times 10^{-23} \mathrm{cm}^{3} \mathrm{s}^{-1}$. Moreover, in the dark matter scenario, the $\tau \bar{\tau}$ annihilation channel is highly suppressed, and a DM model is built to satisfy the fitting results.

Underground Storage of Natural Gas in Hydrate State: Primary Injection Stage

The paper is devoted to simulation of the initial stage of natural gas hydrate underground storage: gas injection into aquifer just below permafrost rocks. It is based on the mathematical model of multiphase non-isothermal real gas and water flow in porous media. The model takes into account the transformation of gas and water into hydrate at certain temperature, which depends on gas flow pressure. The dynamics of hydrate and water saturation as well as the pressure and temperature fields in a reservoir with given porosity, permeability, and initial values of pressure, temperature and water saturation were studied. An implicit finite-difference scheme is used to approximate the original boundary-value problem. The finite-difference equations are solved using simple iteration and sweeping algorithms. Several examples of calculations corresponding to real cases are given. Calculations have revealed that the final result strongly depends on the combination of porosity and permeability of a reservoir.

A novel minimally invasive method of successful tissue glue injection in patients with iatrogenic pseudoaneurysm.

To investigate the efficacy and safety of ultrasound-guided tissue glue injection for the treatment of iatrogenic femoral artery pseudoaneurysm. The study comprised of nine patients with unsuccessful ultrasound-guided thrombin injection and one patient with rapidly progressing anemia. All patients had undergone recanalization procedures at least twice, including two subjects with a very rapidly enlarging pseudoaneurysm lobe or significant anemia. Tissue glue at a dose of 0.9 ± 0.53 ml was injected under ultrasound guidance in each patient. Complete embolization was achieved in all patients. Follow-up ultrasound performed 24 h later as well as at 1 and 2 weeks did not show recurrent reperfusion of the pseudoaneurysm. Embolization of iatrogenic pseudoaneurysm using tissue glue seems to be an effective technique for the treatment of this complication. It might be considered as a treatment option in case of unsuccessful primary repair by means of thrombin injection orhemorrhagic shock due to rapid aneurysm progression. Advances in knowledge: Patients with multiple recanalizations and those with dynamically enlarging pseudoaneurysm or rapidly progressing anemia are at risk of life-threatening bleeding. An ultrasound-guided tissue glue injection, a novel method for the treatment of femoral artery pseudoaneurysm, might be considered as a treatment option especially in case of primary thrombin injection failure.

Prime and Boost Vaccination Elicit a Distinct Innate Myeloid Cell Immune Response

Understanding the innate immune response to vaccination is critical in vaccine design. Here, we studied blood innate myeloid cells after first and second immunization of cynomolgus macaques with the modified vaccinia virus Ankara. The inflammation at the injection site was moderate and resolved faster after the boost. The blood concentration of inflammation markers increased after both injections but was lower after the boost. The numbers of neutrophils, monocytes, and dendritic cells were transiently affected by vaccination, but without any major difference between prime and boost. However, phenotyping deeper those cells with mass cytometry unveiled their high phenotypic diversity with subsets responding differently after each injection, some enriched only after the primary injection and others only after the boost. Actually, the composition in subphenotype already differed just before the boost as compared to just before the prime. Multivariate analysis identified the key features that contributed to these differences. Cell subpopulations best characterizing the post-boost response were more activated, with a stronger expression of markers involved in phagocytosis, antigen presentation, costimulation, chemotaxis, and inflammation. This study revisits innate immunity by demonstrating that, like adaptive immunity, innate myeloid responses differ after one or two immunizations.

Efficacy and safety of repeated courses of hyaluronic acid injections for knee osteoarthritis: A systematic review.

Hyaluronic acid (HA) is a commonly prescribed intra-articular (IA) therapy for knee osteoarthritis (OA). While a single series of IA-HA has been well studied, the efficacy and safety of repeated courses of IA-HA injection therapy in knee OA patients have not been evaluated as frequently. A literature search was conducted using MEDLINE, EMBASE and PubMed databases. The primary outcome measure was knee pain reduction after each treatment course and/or last reported follow-up visit. Secondary outcomes were treatment-related adverse events (AEs) and serious adverse events (SAEs). A total of 17 articles (7 RCTs and 10 cohort studies) met the pre-defined inclusion criteria. Of the RCTs, six were double-blind with two trials including open label extension studies, and one was single-blind. Studies ranged from investigating a single reinjection cycle to four repeat injection cycles. Eleven studies evaluated one reinjection, five studies evaluated ≥2 repeated courses of IA-HA, and one study allowed either one or two repeated courses. All studies reported pain reduction from baseline in the IA-HA treatment group throughout the initial treatment cycle, and either sustained or further reduced pain throughout the repeated courses of treatment. The study with the longest follow-up repeated IA-HA injection every 6 months for 25 months. Pain decreased after the first course and continued to decrease until the end of the study, with an approximate 55% reduction in pain compared to baseline. Common AEs were joint swelling and arthralgia; there were no reported SAEs. All repeated courses were well tolerated, and the number of documented AEs and SAEs was similar to the primary injection regimens. Repeated courses of IA-HA injections are an effective and safe treatment for knee OA. Repeat courses were demonstrated to maintain or further improve pain reduction while introducing no increased safety risk.

Modeling and analysis of selected organization for economic cooperation and development PKL-3 station blackout experiments using TRACE

Abstract A series of tests dedicated to station blackout (SBO) accident scenarios have been recently performed at the Primarkreislauf-Versuchsanlage (primary coolant loop test facility; PKL) facility in the framework of the OECD/NEA PKL-3 project. These investigations address current safety issues related to beyond design basis accident transients with significant core heat up. This work presents a detailed analysis using the best estimate thermal–hydraulic code TRACE (v5.0 Patch4) of different SBO scenarios conducted at the PKL facility; failures of high- and low-pressure safety injection systems together with steam generator (SG) feedwater supply are considered, thus calling for adequate accident management actions and timely implementation of alternative emergency cooling procedures to prevent core meltdown. The presented analysis evaluates the capability of the applied TRACE model of the PKL facility to correctly capture the sequences of events in the different SBO scenarios, namely the SBO tests H2.1, H2.2 run 1 and H2.2 run 2, including symmetric or asymmetric secondary side depressurization, primary side depressurization, accumulator (ACC) injection in the cold legs and secondary side feeding with mobile pump and/or primary side emergency core coolant injection from the fuel pool cooling pump. This study is focused specifically on the prediction of the core exit temperature, which drives the execution of the most relevant accident management actions. This work presents, in particular, the key improvements made to the TRACE model that helped to improve the code predictions, including the modeling of dynamical heat losses, the nodalization of SGs' heat exchanger tubes and the ACCs. Another relevant aspect of this work is to evaluate how well the model simulations of the three different scenarios qualitatively and quantitatively capture the trends and results exhibited by the actual experiments. For instance, how the number of SGs considered for secondary side depressurization affects the heat transfer from primary side; how the discharge capacity of the pressurizer relief valve affects the dynamics of the transient; how ACC initial pressure and nitrogen release affect the grace time between ACC injection and subsequent core heat up; and how well the alternative feeding modes of the secondary and/or primary side with mobile injection pumps affect core quenching and ensure stable long-term core cooling under controlled boiling conditions.

Differences in risk behaviours and HIV status between primary amphetamines and opioid injectors in Estonia and Russia

Background and objectivePeople who inject drugs (PWID) account for over half of new HIV infections in Eastern Europe and central Asia, where opioids continue to be the dominant illicit drugs injected. Stimulants including amphetamines (ATS) have been associated with HIV infection risk in several settings. We sought to examine whether primary ATS injection was associated with greater HIV risk, compared to opioid injection in two European locales with significant HIV epidemics. MethodsPWID in Kohtla-Järve and St. Petersburg were recruited using respondent-driven sampling in 2012–2013. Survey data on demographic characteristics, service use, injecting and sexual risk behaviours and HIV-status (and HCV in Kohtla-Järve) were compared between primary opioid and ATS injectors using logistic regression models. ResultsOf 591 injectors recruited in Kohtla-Järve and 811 in St. Petersburg, 195 (33%) and 27 (4%) primarily injected ATS in each city. In both cities, ATS injectors were younger than opioid injectors, initiated injection later, injected less frequently and were more likely to have been paid for sex. In both cities, PWID had high levels of multiple sex partners. In Kohtla-Järve, ATS-injectors had lower odds of back-loading and greater odds of polydrug use than opioid-injectors. In St. Petersburg, where over half of PWID reported unsafe sharing practices, ATS-injectors were less likely to report these practices. ATS-injection was negatively associated with being HIV positive in Kohtla-Järve (aOR = 0.6; 95%CI: 0.5–0.8) and St. Petersburg (aOR = 0.3; 95%CI: 0.1–0.7). ATS-injection was negatively associated with HCV-reactivity in Kohtla-Järve (aOR = 0.5; 95%CI: 0.3–0.6). ConclusionsIn both locations, primary ATS injection was associated with lower injecting risk behaviours, lower odds of HIV and being paid for sex compared to opioid injection. Interventions targeting the characteristics and needs of ATS injectors are needed to increase contact with services and reduce sexual and injecting risk. Harm reduction services, including sexual risk reduction, need to be expanded for all PWID in St. Petersburg.

Combination Effects of Organic and Inorganic Chromium on Production Performance, Reproductive Response, Immune Status, and Maternal Antibody Transmission in Breeder Quails Under Heat Stress.

This experiment was carried out to investigate the combination effects of organic and inorganic chromium (Cr) on egg production, egg quality, reproductive response, and immune status of breeder quails and their offspring under heat stress. A total of 140 7-week-old Japanese breeder quails (120 females and 20 males) according to a completely randomized design were used in four treatment groups (five replicate and seven birds per each) lasted for 8weeks. Quails exposed to 35°C for 8h/day for induction of cyclic heat stress treatments consisted of diets supplemented with (1) 1mg CrCl3 per kilogram of diet as control (CNT); (2) 1mg Cr-L-Met per kilogram of diet as organic Cr (OCr); (3) 0.5mg CrCl3 plus 0.5mg Cr-L-Met per kilogram of diet (ISO); (4) 1mg CrCl3 plus 0.5mg Cr-L-Met per kilogram of diet (On-top). Productive performance and egg quality parameters were determined weekly. Fertility, hatchability, and embryonic mortality were measured at the end of experiment. Humoral immunity was assessed by primary and secondary antibody titer in sheep red blood cells (SRBC) and Newcastle disease (ND) tests. Cell-mediated immunity was assessed by the cutaneous basophil hypersensitivity (CBH) test to phytohemagglutinin (PHA) at days 20 and 45 of age. White blood cell count and immunoglobulin Y (IgY) content in serum and yolk of breeders and in serum and yolk residues of offspring were also measured. Results showed that maximum egg production, egg shell thickness, and Haugh unit were observed in birds fed ISO and On-top diets (P ≤ 0.05). The highest (P ≤ 0.05) antibody levels in ND test were observed in birds fed with OCr, ISO, and On-top diets. The highest cellular response (P ≤ 0.05) was in 12h after primary PHA injection and 12 and 24h after secondary PHA injection in birds fed with On-top diets. The highest count of heterophil and (H/L) were gained in breeder quails fed with CNT diet, and the lowest of them were reached with On-top diet (P ≤ 0.05). Results showed that the highest IgY level in serum of breeder and their offspring and that of yolk suck and egg yolk were observed in birds fed with On-top diet (P ≤ 0.05). These results suggest that extra supplemental organic Cr in combination with CrCl3 could lead to higher egg production, egg quality, and immune status of breeder quails and their offspring.

A Trp53fl/flPtenfl/fl mouse model of undifferentiated pleomorphic sarcoma mediated by adeno-Cre injection and in vivo bioluminescence imaging.

Genetic mouse models of soft tissue sarcoma provide critical insights into disease pathophysiology, which are oftentimes unable to be extracted from human tumor samples or xenograft models. In this study we describe a mouse model of soft tissue sarcoma mediated by adenoviral-Cre recombinase injection into Trp53fl/fl/Ptenfl/fl lox-stop-lox luciferase mice. Injection of adenovirus expressing Cre recombinase, either subcutaneously or intramuscularly in two experimental groups, results in viral infection and gene recombination with 100% penetrance within the first 24 hours following injection. Luciferase expression measured by real-time bioluminescence imaging increases over time, with an initial robust increase following viral injection, followed by a steady rise over the next several weeks as primary tumors develop and grow. Intramuscular injections were more commonly associated with evidence of systemic viral distribution than subcutaneous injections. All mice developed soft tissue sarcomas at the primary injection site, with histological examination identifying 93% of tumors as invasive pleomorphic sarcomas based on microscopic morphology and immunohistochemical expression of sarcoma markers. A lymphocytic infiltrate was present in 64% of the sarcomas in this immunocompetent model and 71% of tumors expressed PD-L1. This is the first report of a viral-Cre mediated Trp53/Pten mouse model of undifferentiated pleomorphic sarcoma. The bioluminescence imaging feature, along with high penetrance of the model and its immunological characteristics, makes it suited for pre-clinical studies of soft tissue sarcoma.

Experimental Investigation of Spray and Combustion Performances of a Fuel-Staged Low Emission Combustor: Effects of Main Swirl Angle

In order to reduce NOx emissions, modern gas turbines are often equipped with lean-burn combustion systems, where the high-velocity fuel-lean conditions that limit NOx formation in combustors also inhibit the ability of ignition, high altitude relight, and lean combustion stability. To face these issues, internally staged scheme of fuel injection is proposed. Primary and main fuel staging enable fuel distribution control, and multi-injections of main fuel lead to a fast and efficient mixing. A fuel-staged low emission combustor in the framework of lean-burn combustion is developed in the present study, i.e., the central pilot stage for low power conditions is swirl-cup prefilming atomization, the main stage is jet-in-crossflow multi-injection, and a combination of primary and main stage injection is provided for higher power output conditions. In lean-burn combustors, the swirling main air naturally tends to entrain the pilot flame and quench it at low power conditions, which is adverse to the operability specifications, such as ignition, lean blow-out (LBO), and high-altitude relight. In order to investigate the effects of the main swirl angle on combustion performances, the ignition and LBO performances were evaluated in a single dome rectangular combustor. Furthermore, the spray patterns and flow field are characterized by kerosene-planar laser induced fluorescence and particle image velocimetry (PIV) to provide insight into spray and combustion performances. Flow–flow interactions between pilot and main air streams, spray–flow interactions between pilot spray and main air streams, and flame–flow interactions between pilot flame and main air streams are comprehensively analyzed. The entrainment of recirculating main air streams on pilot air streams enhances with the increase of main swirl angle, because of the upward motion and increasing width of main recirculation zone. A small part of droplets are entrained by the recirculating main air streams at periphery of combustor and a majority of droplets concentrate near the centerline of combustor, making that entrainment of recirculating main air streams on pilot spray and quenching effects of recirculating main air streams on pilot flame are slight, and the extinguishing effects can be ignored. The contributions of main swirl strength to improvement of ignition and LBO performances are due to enhancement of air/fuel mixing by strengthening turbulence level in pilot zone.

Isolation of Circulating Tumor Cells in an Orthotopic Mouse Model of Colorectal Cancer.

Despite the advantages of easy applicability and cost-effectiveness, subcutaneous mouse models have severe limitations and do not accurately simulate tumor biology and tumor cell dissemination. Orthotopic mouse models have been introduced to overcome these limitations; however, such models are technically demanding, especially in hollow organs such as the large bowel. In order to produce uniform tumors which reliably grow and metastasize, standardized techniques of tumor cell preparation and injection are critical. We have developed an orthotopic mouse model of colorectal cancer (CRC) which develops highly uniform tumors and can be used for tumor biology studies as well as therapeutic trials. Tumor cells from either primary tumors, 2-dimensional (2D) cell lines or 3-dimensional (3D) organoids are injected into the cecum and, depending on the metastatic potential of the injected tumor cells, form highly metastatic tumors. In addition, CTCs can be found regularly. We here describe the technique of tumor cell preparation from both 2D cell lines and 3D organoids as well as primary tumor tissue, the surgical and injection techniques as well as the isolation of CTCs from the tumor-bearing mice, and present tips for troubleshooting.

Abstract 4869: The Signature Study: Molecular analysis of pediatric tumors with establishment of tumor models in a biology study

Abstract Background: Pediatric cancer is the leading cause of death by disease in children in the US. Significant advances have been made in survival in the past 30 years and genomic understanding of tumors is underway. Gains in the identification of biomarkers, drug targets, and the molecular characterization of cancer are due to improved technology including gene sequencing, proteomics, and epigenetics. Still, this remains limited primarily to large academic centers and patients with high risk/metastatic disease experience &amp;lt; 30% survival. Phase 1/2 trials not based on precision medicine result in poor response rates (&amp;lt;10%). Therefore, genomic understanding of tumors and molecular targeted therapies with aims of reaching all children and reducing toxicity while improving efficacy is needed. Methods: The Signature Study is an IRB-approved biology study that seeks to perform genomic analysis, high throughput (HTP) drug testing, and creation of patient derived xenograft (PDX) models of all pediatric cancer patients diagnosed/relapsed at Helen DeVos Children’s Hospital. Patients are consented, clinical history is collected in RedCap, and tumors are collected flash frozen and in cell culture media. Blood is collected for germline analysis. Tumors are analyzed through gene expression arrays, DNA panels and exomes and RNA sequencing. Tumors in cell culture are used for generation of primary patient cell lines (confirmed by IHC and STR) and immediate injection into NSG mice for PDX models. Cell lines undergo HTP drug testing using the Prestwick and NCI drug libraries, novel therapeutics and combinations. Results: Enrollment has increased since inception in 2011 with now &amp;gt;50 patients/year; a total of 284 pediatric tumors collected representing over 30 tumor types. The most common diagnosis is neuroblastoma, followed by medulloblastoma, osteosarcoma, and rhabdomyosarcoma. Sequencing for genomic analysis has been performed on 166 tumors to identify mutations, fusions, CNV, and deletions. To date 184 have been grown as primary patient cell lines and 75 as PDX models. Over 60 samples have been evaluated in HTP drug testing. Genomic analysis of cultured tumor cells has been correlated with response to drug libraries to establish correlative predictive markers for therapeutic decision making to be tested in clinical trials. The study stores remaining tissue, cell lines, and PDX models for additional future research. Conclusion: This study shows it is feasible for a mid-sized hospital system to coordinate and collect tumors for genomic analysis in real time for clinical decision making in the future. This resource is an integrated TransMed database system which is a powerful resource which correlates clinical outcomes, therapies, genomic sequencing, PDX models and HTP drug testing used to answer research questions of biomarkers, biological characterization, drug sensitivity, and driver pathways within and between pediatric cancers. Citation Format: Elizabeth VanSickle, Ping Zhao, Deanna Mitchell, Jessica Foley, Julie Steinbrecher, Maria Rich, Abhinav Nagulapally, Jeff Bond, William Hendricks, Giselle Saulnier Sholler. The Signature Study: Molecular analysis of pediatric tumors with establishment of tumor models in a biology study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4869. doi:10.1158/1538-7445.AM2017-4869

Does the volume of supplemental intraligamentary injections affect the anaesthetic success rate after a failed primary inferior alveolar nerve block? A randomized-double blind clinical trial.

To investigate the efficacy of 0.2mL vs. 0.6mL of 2% lidocaine when given as a supplementary intraligamentary injection after a failed inferior alveolar nerve block (IANB). Ninety-seven adult patients with symptomatic irreversible pulpits received an IANB and root canal treatment was initiated. Pain during treatment was recorded using a visual analogue scale (Heft-Parker VAS). Patients with unsuccessful anaesthesia (n=78) randomly received intraligamentary injection of either 0.2mL or 0.6mL of 2% lidocaine with 1:80000 epinephrine. Root canal treatment was reinitiated. Success after primary injection or supplementary injection was defined as no or mild pain (HP VAS score ≤54mm) during access preparation and root canal instrumentation. Heart rate was monitored using a finger pulse oximeter. The anaesthetic success rates were analysed with Pearson chi-square test at 5% significance levels. The heart rate changes were analysed using t-tests. The intraligamentary injections with 0.2mL solution gave an anaesthetic success rate of 64%, whilst the 0.6mL was successful in 84% of cases with failed primary IANB. (χ2 =4.3, P=0.03). There was no significant effect of the volume of intraligamentary injection on the change in heart rate. Increasing the volume of intraligamentary injection improved the success rates after a failed primary anaesthetic injection.

Baseline risk factors for drug use among African-American patients during first-month induction/stabilization on methadone

Drug use during methadone induction/stabilization negatively influences later methadone-maintenance-treatment [MMT] outcomes (retention, abstinence). Our study examined the association of baseline risk factors to drug use during the first month of methadone treatment as well as longer-term treatment retention. We conducted these analyses among a race/ethnic minority group at high risk for worse MMT outcomes. African-American MMT patients (N=212) were interviewed at intake to assess clinical (drug use history), psychosocial (close family member substance abuse, psychosocial problems), and demographic factors. Outcomes were first-month opioid+ and cocaine+ urine drug screen [UDS] results and retention (days in treatment). In bivariate analyses, co-occurring cocaine abuse/dependence was associated with worse outcomes for opioid+ UDS, cocaine+ UDS, and retention. Being a primary injection opioid user and residing farther from the clinic were associated with a higher proportion of cocaine+ UDS and shorter retention, respectively. Patients with a significant other substance abuse history provided a higher proportion of both opioid+ and cocaine+ UDS. Sibling and parent substance abuse histories were associated with a higher proportion of opioid+ UDS and shorter retention. Psychosocial problems (economic, housing) were associated with a higher proportion of cocaine+ UDS. In multivariate analyses, co-occurring cocaine abuse/dependence and primary injection opioid use best accounted for first-month opioid+ and cocaine+ UDS, respectively. A higher proportion of first-month opioid+ and cocaine+ UDS and living farther from the clinic accounted for retention. African-American patients reporting baseline risk factors (particularly clinical) experience worse short- and long-term MMT outcomes. Recommendations for improving standards of care are discussed.

Mechanism and influencing factors of EOR by N2 injection in fractured-vuggy carbonate reservoirs

Multi-scale fractures and karst caves are the main reservoir bodies in fractured-vuggy carbonate reservoirs, and there are still various types of remaining oil after water flooding. Oilfield development practices demonstrate that the method of N2 injection can enhance oil recovery effectively. However, the development effect of a single well with gas injection is highly different, and the mechanism and influencing factors of gas injection for enhanced oil recovery are not clear. To reveal the mechanism and influencing factors of enhanced oil recovery through physical experiments and numerical simulation, we have produced a series of physical models of fracture and cave combinations based on the characteristics of this type of reservoir, established a visual physical simulation experimental apparatus and process, and analyzed the main factors affecting the production efficiency of gas injection wells in combination with the actual development of oilfields. The research results demonstrate that the primary types of remaining oil after water flooding in fractured-vuggy carbonate reservoirs are oil at the top of karst caves, oil shielded from high flow channels and oil not swept by the wells. The mechanism of gas injection-enhanced oil recovery is primarily composed of three aspects. First, the injected gas forms a secondary gas cap because of the effect of gravitational differentiation, and the gas cap can displace the remaining oil on top of the karst cave that the injected water cannot drive; Then, injected gas can change the pressure field distribution and the direction of fluid flow after water injection, driving the remaining oil that is shielded by high flow diversion channels; in addition, the injected gas has a certain effect on the reservoir energy supply. The geological conditions, such as the remaining reserves of injecting gas wells, filling level, well-reservoir position relationship and bottom water energy, have great influence on the development effect. The starting time of gas injection has an optimal point, and injecting too early or late will affect the oil recovery. The cyclic gas injection quantity and gas injection velocity are the primary injection production parameters that influence the production effect of a gas injection well. Finally, the principle of selecting a well for gas injection according to the research results is discussed, which can provide reference for selecting gas injection wells and injection methods of fractured-vuggy reservoirs in Tahe Oilfield.

X-ray imaging of horizontal jets in gas fluidised bed nozzles

The design of the fluidising air distributors, or nozzles, is one of the most important aspects influencing operation of fluidised beds at industrial scale. In this work, the study of the hydrodynamics in gas-solid fluidized beds where the primary gas injection is achieved through a nozzle-type gas distributor has been carried out, using an innovative X-ray imaging technique. Qualitative and quantitative results are reported, with particular focus on jets penetration length and their evolution. Results show that the lighter and the finer are the particles, the larger is the jet penetration. Since the experimental data do not match predictions available in literature, a new non-dimensional correlation based on hydrodynamic scaling and Froude number is also proposed. The new correlation takes into account the effects of jet velocity, particle density and particle size. A tentative mechanistic explanation for the departure from purely hydrodynamic scaling is offered.