Drop Of Saline Research Articles

Improving the assessment of agricultural land reclamation condition using GIS based on the interdependence of the factors impact

Land used for agriculture is critical in Uzbekistan and throughout the world. Land reclamation is assessed using a variety of traditional approaches. The creation of land reclamation assessment methods is becoming more common as a result of the usage of modern geoinformation technologies and their better methodology. The levels of mineralization in the groundwater level, as well as NDVI and NDSI analysis, were determined for the three months of 2020 and 2021 - April, July, and November - in the irrigated lands of the Yuqiri chirchik, Urtachirchik, and Quyichirchik districts of the Tashkent region, which were used as the research object. These data were reclassified in ArcGIS software, and fields were defined by values. Their correlation was determined based on the results provided above. It was determined that plant vegetation is dependent on the salinity and mineralization of seepage waters, i.e., a decrease in seepage water mineralization and a drop in salinity are directly associated to an increase in plant vegetation, and vice versa.

Prevalenţa infecţiei cu Trichomonas vaginalis la femeile de vârstă reproductivă din Kosovo

Aim. This study was undertaken to determine the prevalence of Trichomonas vaginalis infection in women of reproductive age from Kosovo. Methodology. The study was carried out in the Obstetrics and Gynecology Clinic of the Faculty of Medicine, University of Pristine, Kosovo, between April and July 2022. The study population consisted of a total of 207 women. Sexually active women aged at least 20 years old were included in the study. A semi-structured questionnaire was distributed to the participants to seek for information such as age, marital status, occupation and pregnancy status. Every woman’s informed consent was sought before the collection of specimens by qualified medical personnel. The specimens were carefully and aseptically collected from the high vaginal area using well-labeled, sterile, non-abrasive high vaginal swab sticks. A few drops of normal saline were added to each swab stick, and a wet mount examination was performed within less than half an hour of collection in order to get optimal results. The wet preparation of the vaginal discharge was made by applying a drop from the sample to a small area of a clean glass slide with a cover slip in order not to trap air bubbles. The wet smear was examined microscopically for motile T. vaginalis with a low-power objective (x10) and then with a high-power objective (x40). The vaginal secretion was characterized by the presence of epithelial cells, white blood cells and red blood cells. The T. vaginalis trophozoite was identified by its oval, flagellated and distinctive motility (jerky movement). Results. An overall prevalence rate of 12.56% was found in Kosovo. The prevalence of T. vaginalis infection differed from place to place. It varied as well among age groups, showing the highest prevalence in the age group of 30-39 years old (13.63%), and the lowest in the age group of 20-29 years old (5.70%). The prevalence varied with marital groups, being the highest in divorced women (30.76%) and the lowest among singles (6.74%). The prevalence rate was also observed to be highest among the employed (19.71%) and lowest among students (14.81%) and unemployed (7.33%). T. vaginalis infection was observed in non-pregnant women in a prevalence rate of 15.20%. Conclusions. T. vaginalis infection is prevalent in women of reproductive age, as evident in our country. The infection is common in sexually active female participants, especially in those with multiple sex partners. Proper personal hygiene, faithfulness to one sexual partner, and massive public awareness on the prevention and control of T. vaginalis are advised to reduce its prevalence among women of reproductive age in our country.

Medical treatment of otitis media with effusion using fluticasone propionate nasal spray

Objective: To determine how well fluticasone propionate aqueous nasal spray worked to reduce fluid buildup in the middle ear, a condition known as middle ear effusion. Methodology: This comparative interventional clinical study involving 70 patients with otitis media with effusion (OME) was conducted in Al-Sader Medical City in Najaf from December 2020 and January 2022. Participants had their parents' medical history and ENT exam. OME signs. These included child hearing loss and school failure. OME Otoscopy verified. Pure-tone audiometry and tympanometry followed. Group A received 100 micrograms/day (50 per nostril) fluticasone propionate aqueous nasal spray (NSS-nasal steroid spray) for 12 weeks. NS drops for B. All patients received four-week follow-up calls. Each appointment included otoscopy and audiology. Normal otoscope, type A tympanogram, and better hearing resolved OME. Results: Nasal steroids helped 40 (NSS). 35 nasal saline drop (NS) patients were 4–13 years old, averaging 8.2. After 12 weeks, group A patient who used the intranasal steroid spray exhibited a definite subjective hearing improvement, but group B patients who used nasal saline drops did not. 75% of intranasal steroid patients had type A tympanometry curves after three months (p< 0.00001). Group A intra nasal steroid spray decreased PTA from 35 dB to 15 dB. Nasal saline drop patients had 25 dB PTA. Conclusion: One effective therapy for OME is the use of a steroid nasal spray. It's much safer to use now. Research on its long-term and repeated applications is necessary.

Effects of contact lens wearing on corneal sensitivity and reflex functions

AbstractPurpose: To study the effects of contact lens (CL) use on corneal sensory nerve activity, exploring corneal sensitivity and ocular functions regulated by sensory input in asymptomatic (CL‐A) and symptomatic (CL‐S) CL wearers.Methods: CL wearers (23.8 ± 1.0 years; n = 31) participating in the study were classified as CL‐S when OSDI ≥13. Sex and age eye glasses (EG) users (24.5 ± 0.8 years, n = 29) participated as control group. Corneal mechanical, chemical and cold sensitivity was explored using a gas esthesiometer and 4°C‐saline drops; intensity, irritation and cold components of the evoked sensation were measured with Visual Analogue Scales (VASs). Tear volume (with phenol red threads), tear stability (TBUT), basal blinking frequency (BF), ocular surface temperature (OST; by IR thermography) were also assessed.Results: CL wearers scored higher irritation VAS values than EG wearers for mechanical (2.5 ± 0.5 vs. 1.4 ± 0.4 for 160 ml/min air flow, CL vs EG, p = 0.09) and chemical stimuli (1.8 ± 0.5 vs. 0.7 ± 0.3 for 40% CO2, p < 0.05), and lower intensity values for cold stimulation (2.2 ± 0.4 vs. 4.5 ± 0.7, p < 0.05); tear volume was similar (27.0 ± 2.2 vs. 27.2 ± 1.6 mm), TBUT lower (8.3 ± 0.5 vs. 11.7 ± 0.5 s, p < 0.001), BF was higher (25.1 ± 2.4 vs. 14.3 ± 1.9 blinks/min, p < 0.001), and OST was lower (34.4 ± 0.2 vs. 35.2 ± 0.2°C, p < 0.01). VAS values for cold stimulation was slightly lower in CL‐S than in CL‐A (2.0 ± 0.4 vs. 4.0 ± 0.8, p = 0.06), while OST was higher (35.0 ± 0.2 vs. 33.9 ± 0.3°C, p < 0.01).Conclusions: CL wearing affects corneal sensory nerve functions, changing corneal sensitivity, blinking rate, tearing stability, and OST. The changes found in corneal sensitivity fully agree with those described in neural activity of corneal sensory nerves after injury or inflammation using animal models: sensitization of corneal nociceptors and inhibition of cold thermoreceptors. The differences between CL‐S and CL‐A wearers could be due to the presence of subclinical ocular surface inflammation in symptomatic subjects.

Widespread declines in water salinity of the endorheic Tibetan Plateau lakes

The Tibetan Plateau (TP) hosts more than one thousand lakes (>1km2) in its endorheic basins. The changing climate in recent decades has led to significant modifications in the endorheic hydrologic system. Most TP lakes experienced dramatically expanding areas, rising water levels, and increasing storage, which inevitably influenced the lake salinity. This study provides a regional-scale investigation of water salinity changes of the TP lakes (for 83 lakes with two-epoch salinity records, among the approximately 160 lakes >50km2) by synthesizing multi-source data around the 1970s and 2010s. Our results reveal lake salinity has considerably declined for most expanding lakes across the endorheic basins. The mean salinity of 62 terminal lakes dropped from 92.76 g l−1 to 42.00 g l−1 during the 1970s–2010s, in contrast to the slight variations (3.42 g l−1 to 1.48 g l−1) of the 21 exorheic or upstream lakes. As a result, many hypersaline lakes have become polysaline or oligosaline lakes, such as Cedo Caka, Norma Co, etc. In particular, some large lakes (e.g., Siling Co, ‘Twin Lakes’, and Ayakkum Lake) also experienced significant drops in water salinity, with the exceptional cases for Nam Co and Qinghai Lake probably due to the relatively low ratios of increased water mass to their net storages. The widespread declining water salinities could greatly influence bacterial richness, diversity, and evenness, and affect the aquatic carbon cycle and utilization in the high-altitude endorheic lakes. More attention should be paid on understanding the saline lake ecosystem evolution and the regional carbon cycle in response to changing water salinity of the TP lakes.

Genital Examination of the Prepubertal Female: Essentials for Pediatric Nurse Practitioners.

Genital Examination of the Prepubertal Female: Essentials for Pediatric Nurse Practitioners.

Midazolam-Dexmedetomidine Combination versus Midazolam Alone for Premedication in Children Undergoing Pediatric Cataract Surgeries: a Double‐Blinded Randomized Controlled Trial

Background: Dexmedetomidine, a selective α2 agonist has shown promising results when used as a premedicant. This prospective randomized study evaluated the efficacy of two different premedication regimens in achieving a smooth conduct of anesthesia and optimum pain relief in pediatric cataract surgeries. Methods: 90 ASA I or II children, aged 1-6 years, scheduled for elective cataract surgeries were randomized to receive either 0.25 mg kg-1oral midazolam and 1μg kg-1 of intranasal dexmedetomidine (Group MD; n=45) or 0.5mg/kg oral midazolam followed by 0.02ml kg-1 intranasal saline drops (Group MS; n=45) 45 min prior to surgery. Drug acceptance, anxiety at parental separation and quality of mask induction was evaluated. Subtenon block was given to all the children. Intraoperative use of narcotics was avoided and used only as rescue drug. Primary outcome of the study was number of patients requiring rescue analgesia over 24-hour period. The secondary outcomes were time to first rescue analgesia, frequency of rescue analgesia, incidence of OCR and PONV. Results: 90% of the children in Group MD achieved MOAA/S ≤ 4 at 30 minutes versus 95% in Group MS. Drug acceptability, parental separation and mask acceptance were similar in both groups. Incidence of PONV and children who required rescue analgesia was less in MD group compared with MS group. There was no event of OCR in both groups. Conclusion: Premedication with combined IND and low dose oral midazolam is superior in decreasing postoperative analgesic requirements when compared to routine oral midazolam premedication alone in pediatric cataract surgeries under general anesthesia.

Effectiveness of Bovine Tunica Vaginalis Powder in the Prevention of Tendon Adherence Following Tendon Repair Process in Bucks

The current study was designed to investigate the efficacy of lyophilized bovine tunica vaginalis powder on peritendinous adhesion of induced defect in superficial digital flexor tendon (SDFT) in goats. The study was carried out on 18 adult bucks, the surgical procedure was done under highly aseptic conditions. Prior to surgery, animals were sedated by intramuscular injection of 2 % xylazine in a dose 0.5 mg/kg body weight, then the site of the operation is anesthetized by linear infiltration of 2% lidocaine hydrochloride. The surgical incision is made on the skin on the palmer surface of the metacarpal bone of the left forelimb to expose the (SDFT), a (0.1 depth, 0.2 width, and l Long) cm defect is made on the exposed tendon, this gap is filled with drops of sterile normal saline in (9) animals, and mentioned as a control group, while the gap of the rest (9) animals is filled with the lyophilized powder as treated group. Subcutaneous tissue was closed using absorbable suture material by simple continuous suture technique, and a simple interrupted suture mattress using non-absorbable suture material for closing the skin. The macroscopic findings exhibited a significant difference in adhesion scores between the 2nd, and 3rd periods of assessment post-operation in the first and second groups, with no significant differences between groups. The conclusion of this study is the tunica vaginalis scaffold has no obvious effect on decreasing adhesion between a tendon and surrounding tissues.

Экспериментальная модель хронического воспаления тканей глазной поверхности, ассоциированного с медикаментозным лечением глаукомы

Purpose. To study experimental model of eye surface chronic inflammation, associated with glaucoma medication. Material and methods. 40 rabbits received glaucoma medication containing prostaglandin analogue (PGA), beta-blocker (BB) and preservative benzalkonium chloride (PGA + BB group) for 3 months. Rabbits of control group (n=12) received drops of normal saline for the same period of time. All the rabbits underwent regular ophthalmic examination including biomicroscopy, conjunctival hyperemia scoring, corneal examination involving fluorescein staining as well as Shirmer's test I. In 3 months tissues of conjunctiva, Tenon's capsule and cornea were histologically investigated by means of microscopy. Results. Median score of conjunctival hyperemia was significantly higher at PGA + BB group by the end of the study: 2.0 (1.0; 2.0) vs 0.0 (0.0; 0.5) points in control group. Corneal epithelium damage score according to Efron grading scales was 2.0 (1.0; 2.0) points in PGA+BB group, while corneas of control group rabbits didn't show signs of fluorescein staining. Rabbits under topical glaucoma medication had lower results of Shirmer's test I: 10.0 (9.5; 11.0) mm vs 14.0 (14.0; 15.0) mm at animals of control group by the end of experiment. Histological examination revealed thickened conjunctiva, thickened conjunctival epithelium with disorganization of its layers, lesions of monocyte infiltration, fibrosis and neoangiogenesis in conjunctiva and Tenon's capsule, as well as local detachment of upper layers of corneal epithelium in PGA + BB group. Conclusion. We received experimental model of eye surface disease, associated with glaucoma medication, as a result of daily 3-months administration of fixed combination of PGA and BB containing preservative in rabbit eyes. Eye surface disorder was characterized by morphological signs of chronic inflammation of conjunctiva and Tenon's capsule with clinical manifestations of dry eye disease. Key words: glaucoma medication, preservatives, experimental model, dr y eye disease, inflammation, conjunctiva

A study on cognitive impairment of mice exposed to nano-alumina particles by nasal drip

BackgroundAs an emerging nanomaterial, nano-alumina is widely used in chemical engineering, food and medicine due to its special physical and chemical properties, and its potential health hazards have attracted attention. ObjectiveAim of this study is to understanding the effect and possible mechanism of nano-alumina on cognitive function in mice. MethodsMale healthy ICR mice were randomly assigned and given nasal drops of saline, nano-alumina (different doses) and micro-alumina for 30 days, respectively. Morris water maze test, step down test and open field test were used to detect learning and memory ability. Blood brain permeability was observed by immunofluorescence staining and lanthanum nitrate tracing, histopathological abnormalities in mice hippocampus was observed by thionine staining, the final determination of oxidative stress level in brain tissue was measured by using oxidative stress index detection kit and the level of LC3-Ⅱ and Caspase-3, 8, 9 proteins were detected by western blot. ResultsIn the cerebral cortex of mice exposed to nano-alumina particles, lanthanum nitrate particles adhered to vascular endothelial cells, and the expression of ZO-1 and Occuldin decreased and morphology was disordered; most neurons in hippocampus CA3 region showed balloon-like swelling and degeneration, nucleoli disappeared and apical dendrites broke; mice exposed to nano-alumina, the escape latency in Morris water maze increased compared with the control group(P < 0.05),and the residence time in the original platform quadrant shortened significantly(P < 0.05);the platform latency was significantly shortened and the number of errors increased in the step down test compared with the control group; the residence time in the center of mice the nano-alumina treated was significantly increased in open field test (P < 0.05). ConclusionThe nano-alumina particles could be transported into the central nervous system via blood-brain barrier and olfactory bulb, impair learning and memory function in mice, which is more serious than the micro-alumina particles. The apoptosis of mice neurons caused by nano-alumina particles maybe due to the mixed neurotoxic effect of oxidative stress and the elemental toxicity of aluminum itself.

Response of Prokaryotic Communities to Freshwater Salinization

Each year, millions of tons of sodium chloride are dumped on roads, contributing to the salinization of freshwater environments. Thus, we sought to understand the effect of sodium chloride (NaCl) on freshwater lake prokaryotic communities, an important and understudied component of food webs. Using mesocosms with 0.01–2.74 ppt NaCl (0.27–1110.86 mg/L Cl−), we evaluated the effect generated on the diversity and absolute abundance of prokaryotic populations after three and six weeks. A positive relationship between Cl− values and absolute bacterial abundance was found after three weeks. The influence of eukaryotic diversity variation was observed as well. Significant differentiation of bacterial communities starting at 420 mg/L Cl− was observed after three weeks, levels lower than the Canadian and US recommendations for acute chloride exposure. The partial recovery of a “pre-disturbance” community was observed following a drop in salinity at the threshold level of 420 mg/L Cl−. A gradual transition of dominance from Betaproteobacteria and Actinobacteria to Bacteroidia and Alphaproteobacteria was observed and is overall similar to the natural transition observed in estuaries.

Synergistic Interaction of Low Salinity Stress With Vibrio Infection Causes Mass Mortalities in the Oyster by Inducing Host Microflora Imbalance and Immune Dysregulation.

A sudden drop in salinity following extreme precipitation events usually causes mass mortality of oysters exposed to pathogens in ocean environment. While how low salinity stress interacts with pathogens to cause mass mortality remains obscure. In this study, we performed an experiment by low salinity stress and pathogen infection with Vibrio alginolyticus to investigate their synergistic effect on the mortality of the Pacific oyster toward understanding of the interaction among environment, host, and pathogen. We showed that low salinity stress did not significantly affect proliferation and virulence of V. alginolyticus, but significantly altered microbial composition and immune response of infected oysters. Microbial community profiling by 16S rRNA amplicon sequencing revealed disrupted homeostasis of digestive bacterial microbiota with the abundance of several pathogenic bacteria being increased, which may affect the pathogenesis in infected oysters. Transcriptome profiling of infected oysters revealed that a large number of genes associated with apoptosis and inflammation were significantly upregulated under low salinity, suggesting that low salinity stress may have triggered immune dysregulation in infected oysters. Our results suggest that host-pathogen interactions are strongly affected by low salinity stress, which is of great significance for assessing future environmental risk of pathogenic diseases, decoding the interaction among environment, host genetics and commensal microbes, and disease surveillance in the oyster.

Measuring and modeling the influence of salinity change on the transport behaviour of Escherichia coli through quartz sand

Pathogenic bacteria can be discharged in the environment through natural as well as anthropogenic activities. Once in the environment, they may contaminate soil and sediments and migrate towards water bodies. Transient chemical conditions may occur in soil/sediments and favor mobilization of bacteria, e.g., upon the reduction of salinity (or ionic strength). However, the magnitude of this phenomenon and its relationship with particle size is not well understood, yet.In this work, we investigated the transport of Escherichia coli under variable salinity conditions (between 1 and 20 part per thousand, ppt) and for different soil grain sizes (between 150 and 710 μm). A model developed in our group was applied in this work. It couples bacteria and salinity transport equations in order to account for transient water composition in the description of bacteria migration. The model was calibrated and validated with laboratory experiments. The tests were monitored continuously with UV–Vis spectroscopy, which allowed to record highly resolved concentration fronts. The results show that salinity increases the retardation of the bacteria. Upon salinity drop, a release of bacteria occurs forming a peak whose magnitude increases with salinity change. This effect becomes more important as the grain size decreases. Simulations suggest that the dominant retention mechanism is attachment for coarse sand and straining for fine sand. The retention can be reversed as the salinity is reduced causing a sudden bacteria mobilization. Such a behaviour may have important implications on microbial contamination of water bodies when soil/sediments undergo transient chemical conditions.

Genesis of "negative pressure" during hanging drop; the answer is positive pressure.

A drop of saline placed within the hub of an epidural needle is sucked in when the needle is advanced and penetrates through a polyurethane foam cube. This phenomenon might be explained by the release of compressed air inside of the needle into the air. The positive pressure inside of the needle may be generated by advancing of the needle. To prove this hypothesis, the pressure inside of the needle was measured during needle advancement, and it increased gradually and then dropped to zero suddenly when the needle fully penetrated the polyurethane foam block. We can speculate that the same phenomenon occurs during hanging-drop method of epidural anesthesia, and this may occur regardless of whether epidural subatmospheric pressure exists or not.

Optimal Device and Regimen of Nasal Saline Treatment for Sinonasal Diseases: Systematic Review.

ObjectiveThis review aimed to systematically determine the optimal nasal saline regimen for different types of sinonasal diseases.Data SourcesPubMed, Embase, SCOPUS, Cochrane Library, Web of Science, ClinicalTrials.gov. The last search was on December 6, 2021.Review MethodsStudy selection was done by 2 independent authors. Randomized controlled trials and meta-analyses were included. The effects of nasal saline treatment through various devices, saline tonicities, and buffer statuses were evaluated in patients with allergic and nonallergic rhinitis, acute and chronic rhinosinusitis (CRS), CRS with cystic fibrosis, and postoperative care, including septoplasty/turbinoplasty and endoscopic sinus surgery.ResultsSixty-nine studies were included: 10 meta-analyses and 59 randomized controlled trials. For allergic rhinitis, large-volume devices (≥60 mL) were effective for treating adults, while low-volume devices (5-59 mL) were effective for children. Isotonic saline was preferred over hypertonic saline due to fewer adverse events. For acute rhinosinusitis, saline irrigation was beneficial in children, but it was an option for adults. Large-volume devices were more effective, especially in the common cold subgroup. For CRS, large-volume devices were effective for adults, but saline drop was the only regimen that had available data in children. Buffered isotonic saline was more tolerable than nonbuffered or hypertonic saline. The data for CRS with cystic fibrosis and nonallergic rhinitis were limited. For postoperative care, buffered isotonic saline delivered by large-volume devices was effective.ConclusionNasal saline treatment is recommended for treating most sinonasal diseases. Optimal delivery methods for each condition should be considered to achieve therapeutic effects of saline treatment.

Evolution, Causes and Influence Factors of Taal Volcanic Activities

Volcanoes are a kind of geological feature which can bring both destruction and wealth to human beings. This study takes the eruption of Taal Volcano on January 12, 2020 as an example to analyze its eruption evolution, causes and influence factors via QGIS software. Taal Volcano lies at the southwestern end of a convergent boundary between the Eurasian and Philippine Sea tectonic plates where volcanic activities are frequent. Results show that the evolution of the eruption consists of increased CO2 flux, seismic swarms, phreatic explosion chronically. The origin of the volcano is the subduction of the oceanic plate and terrestrial plate. Volcanic eruptions are mostly due to pressurization by active convergent plates activities. The eruption emitted tephra and gas, which exerted impacts on the atmosphere, the nearby vegetation and the water body, and was predicted to result in an El Nino. High concentration of particles, dispersed tephra output, a sharp increase in SO2 and CO content, variation in atmospheric ozone, and rise in humidity were observed in the atmosphere following the eruption. The volcanic output wiped out the plant cover on the volcano island, and covered the vegetation outside of the volcano island, as shown in the RGB band composite and land cover change monitoring images generated using QGIS from Sentinel-2 data. The volcanic output’s influences on nearby water bodies were shown through drops in ocean salinity and Taal lake’s PH, variation in ocean temperature, and increased ocean’s surface latent heat flux.

The Key Impact on Water Quality of Coral Reefs in Kenting National Park

Southern Taiwan’s Kenting National Park is a popular retreating place for many domestic and international tourists, with increasing tourist numbers potentially over-burdening the coastal ecosystems. To better understand human impacts, a long-term ecological research program was initiated in 2001 to track water quality at 14 coral reef-abutting sites throughout the park since then. Extracting the data from this 20-year survey, we found that increasing in the nutrient levels during the summer rainy season, together with the drops in salinity led by freshwater inputs (land- &amp; rainfall-derived), was the main impact to coral reef ecosystem of Kenting. Cluster analysis further confirmed the nutrient influx was mainly attributed to the local discharge outlets with dense of villages and hotels at upstream. Therefore, more efforts are needed to input to control tourist number, treat waste water discharge and strengthen land protection facilities.

Oyster shells, bulk carbonate sediment, and meteoric calcite cement as recorders of oceanic and radiogenic 87Sr/86Sr in mixed heterozoan carbonates and terrigenous sediment

ABSTRACT Well-preserved oyster shells from mixed heterozoan carbonates and terrigenous sediments of Miocene age in the La Chanata area (southern Spain) show varying luminescence and covarying δ18O and δ13C compositions &amp;gt; –2‰ VPDB. Temperature and salinity modeling based on the δ18O give temperatures ranging from 13 to 33 °C (average 22.4 °C) and normal-marine salinities (34–37 PSU). The isotopic compositions likely reflect environmental conditions during shell secretion; moreover, their identical intra-shell 87Sr/86Sr compositions (equal to or less than the analytical precision of 20 × 10–6) support a primary origin. Additional information from δ18O and 87Sr/86Sr compositions of Heterostegina foraminifera and sediment and cement samples show that: a) bulk sediment and cement samples that have significantly lower δ18O and δ13C values but 87Sr/86Sr values similar to the oyster shells likely derived their isotopic compositions from intraformational dissolution of high-Mg calcite and aragonite allochems in meteoric groundwaters, b) cement samples that have the lowest recorded δ18O and δ13C compositions (&amp;lt; –6.5‰ VPDB) and highest 87Sr/86Sr ratios (&amp;gt; 0.709198) record meteoric diagenesis where the strontium was derived mainly from weathering of the uplifted Alpujárride bedrock, whereas c) bulk sediment and Heterostegina foraminifera with intermediate 87Sr/86Sr values likely received their strontium from weathering of the surrounding bedrock as well as dissolution of intraformational carbonates and possibly overlying Messinian marls (now eroded). Oysters with intermediate 87Sr/86Sr ratios likely secreted their shell parts during transient salinity drops (down to 16 PSU) when rivers and submarine groundwater discharge supplied radiogenic strontium to the nearshore environment. Numerical age determination of sediment samples and oyster shells that have similar (within the analytical precision) 87Sr/86Sr ratios indicate a late Tortonian age (8.1 Ma) of the La Chanata deposits.

1287. Double Disk Diffusion Study to Evaluate the Synergistic Effect Between Cefiderocol and Ceftazidime-Avibactam Against Cefiderocol-Non-susceptible Acinetobacter baumannii

Abstract Background Cefiderocol (CFDC), a siderophore cephalosporin, has broad coverage of Gram-negative bacteria and has been approved for clinical use in USA and Europe. The SIDERO-WT surveillance studies showed that CFDC shows &amp;gt;95% susceptibility against Acinetobacter baumannii. Against many of CFDC non-susceptible isolates, most of which had blaPER gene, the combination use of avibactam significantly decreased the MIC by broth microdilution (BMD). In this study, we evaluated the appropriate methodology to evaluate the synergistic effect by disk diffusion studies. Methods The susceptibility testing was conducted as recommended by the CLSI using CFDC non-susceptible isolates (MIC of &amp;gt;4 µg/mL based on CLSI breakpoint). The MIC by BMD was determined using iron-depleted cation-adjusted Mueller-Hinton broth, in the presence or absence of 4 µg/mL of avibactam. The disk diffusion was evaluated using Mueller-Hinton agar, and the synergy was evaluated by using disk stacking methods. For disk stacking methods, CFDC disk was placed on agar on which bacterial suspension of 0.5 McFarland units was spread, then the ceftazidime-avibactam (CZA) disks was stacked on the top, followed by adding a drop (30 µL) of saline on the stacked disks. As an alternative method, CZA was immersed in saline for 1 second instead of adding a drop of saline, followed by the stacking on the top. The disk zone size was determined after 24-hour incubation at 37°C. Results Against blaPER-positive A. baumannii which showed &amp;gt;64 µg/mL MIC of CFDC and CZA, CFDC MIC decreased to 0.25 µg/mL in the presence of avibactam. The disk diffusion methods also showed isolates resistant to CFDC and CZA and showed susceptiblilty disk zone to CFDC by stacking both disks. On the other hand, against blaNDM-positive A. baumannii which showed 64 µg/mL MIC of CFDC and CZA, the disk diffusion methods showed resistance even when stacking both disks. Against multiple isolates, the MIC of CFDC without or with avibactam was correlated well with the disk zone produced by CFDC disk alone or stacked with CZA disks, respectively (Figure). Conclusion The synergistic effect between CFDC and avibactam by BMD methods could be detected by disk stacking methodology using CFDC and CZA disks. Disclosures Yoshinori Yamano, PhD, Shionogi (Employee) Miki Takemura, MS, SHIONOGI &amp; CO., LTD. (Employee) Roger Echols, MD, Shionogi (Consultant) Christopher Longshaw, PhD, Shionogi (Employee)

AAUS guidelines 2021 revision sexually transmitted infection (STIs) diagnostic strategy for STI

AAUS guidelines 2021 revision sexually transmitted infection (STIs) diagnostic strategy for STI