Coordination of dissolved transition metals in pristine battery electrolyte solutions determined by NMR and EPR spectroscopy.

The solvation of dissolved transition metal ions in lithium-ion battery electrolytes is not well-characterised experimentally, although it is important for battery degradation mechanisms governed by metal dissolution, deposition, and reactivity in solution. This work identifies the coordinating species in the Mn2+ and Ni2+ solvation spheres in LiPF6/LiTFSI-carbonate electrolyte solutions by examining the electron-nuclear spin interactions, which are probed by pulsed EPR and paramagnetic NMR spectroscopy. These techniques investigate solvation in frozen electrolytes and in the liquid state at ambient temperature, respectively, also probing the bound states and dynamics of the complexes involving the ions. Mn2+ and Ni2+ are shown to primarily coordinate to ethylene carbonate (EC) in the first coordination sphere, while PF6- is found primarily in the second coordination sphere, although a degree of contact ion pairing does appear to occur, particularly in electrolytes with low EC concentrations. NMR results suggest that Mn2+ coordinates more strongly to PF6- than to TFSI-, while the opposite is true for Ni2+. This work provides a framework to experimentally determine the coordination spheres of paramagnetic metals in battery electrolyte solutions.

Systemic prime mucosal boost significantly increases protective efficacy of bivalent RSV influenza viral vectored vaccine.

Although licensed vaccines against influenza virus have been successful in reducing pathogen-mediated disease, they have been less effective at preventing viral infection of the airways and current seasonal updates to influenza vaccines do not always successfully accommodate viral drift. Most licensed influenza and recently licensed RSV vaccines are administered via the intramuscular route. Alternative immunisation strategies, such as intranasal vaccinations, and "prime-pull" regimens, may deliver a more sterilising form of protection against respiratory viruses. A bivalent ChAdOx1-based vaccine (ChAdOx1-NP + M1-RSVF) encoding conserved nucleoprotein and matrix 1 proteins from influenza A virus and a modified pre-fusion stabilised RSV A F protein, was designed, developed and tested in preclinical animal models. The aim was to induce broad, cross-protective tissue-resident T cells against heterotypic influenza viruses and neutralising antibodies against RSV in the respiratory mucosa and systemically. When administered via an intramuscular prime-intranasal boost (IM-IN) regimen in mice, superior protection was generated against challenge with either RSV A, Influenza A H3N2 or H1N1. These results support further clinical development of a pan influenza & RSV vaccine administered in a prime-pull regimen.

The first 100 days after childbirth: cross-sectional study of maternal clinical events and health needs from primary care.

BACKGROUND: The first 100 days after childbirth are important for women recovering from pregnancy and birth. AIM: To describe the most common clinical events or health needs documented in women's primary care records in the first 100 days after childbirth. DESIGN AND SETTING: Cross-sectional study using electronic health records from United Kingdom primary care data. METHOD: We examined the primary care records from childbirth up to 100 days after childbirth of women aged 16-49 years who had given birth to a single live infant 2006-2016 in IMRD. We identified the most common clinical events or health needs based on documented symptoms, diagnoses and medications. We explored how these varied by patient characteristic. RESULTS: We identified 925,712 contacts during the 100 days following 309,573 births. We found that women were most likely to use primary care to have a postnatal visit or check (60.6%), for monitoring (such as a blood pressure reading) (49.9%), and to access contraception (49.7%). Younger women were more likely to have contacts for preventative care compared to older women but were less likely to have contacts for ongoing mental and physical symptoms or conditions, and pre-existing conditions. The highest peak in contacts occurred 42 days after birth, and related to a postnatal check or visit, monitoring a patient and recording lifestyle factors (such as smoking status). CONCLUSION: Primary care services should seek to match the needs of new mothers taking account of a high volume of contacts for a broad range of planned and responsive care following childbirth.

Could primary care records be used to identify women at risk of perinatal anxiety? A mixed-methods study.

BACKGROUND: Perinatal anxiety (PNA) occurs throughout the antenatal period or up to 1 year after childbirth, with a prevalence of 21%. AIM: To investigate if primary care records could be used to identify women at 'higher risk' of PNA. METHOD: Mixed-methods approach using quantitative and qualitative methods. Quantitative data analysis used Clinical Practice Research Datalink and IQVIA Medical Research Data to identify risk factors for PNA. Interviews explored the lived experiences of women with PNA about predisposing factors for PNA and acceptability of being informed of risk; and perspectives of primary healthcare professionals and Voluntary, Community, and Social Enterprise practitioners about risk communication. Interviews were conducted online, digitally recorded with consent, transcribed, and anonymised prior to analysis. Data were thematically analysed. Patient and clinical advisory groups informed each stage of the research. RESULTS: Women reflected on both positive and negative impacts of being identified at higher risk of PNA, a lack of understanding of how primary care records are used, and who has access to them. All interview participants suggested predisposing factors that would not be coded in primary care records. Quantitative analysis demonstrated that some predisposing factors for PNA can be identified in a woman's primary care records. Initial analysis suggests associations between PNA and infant health and healthcare use. CONCLUSION: While identification of higher risk of PNA may be acceptable, some factors that may contribute to PNA are not coded in primary care records. Identifying and managing PNA is needed to improve infant health.

Quantifying the costs of hospital admission for families of children with a febrile illness in the North East of England.

OBJECTIVE: To assess the financial non-medical out-of-pocket costs of hospital admissions for children with a febrile illness. DESIGN: Single-centre survey-based study conducted between March and November 2022. SETTING: Tertiary level children's hospital in the North East of England. PARTICIPANTS: Families of patients with febrile illness attending the paediatric emergency department MAIN OUTCOME MEASURES: Non-medical out-of-pocket costs for the admission were estimated by participants including: transport, food and drinks, child care, miscellaneous costs and loss of earnings. RESULTS: 83 families completed the survey. 79 families (95.2%) reported non-medical out-of-pocket costs and 19 (22.9%) reported financial hardship following their child's admission.Total costs per day of admission were median £56.25 (IQR £32.10-157.25). The majority of families reported incurring transport (N=75) and food and drinks (N=71) costs. CONCLUSIONS: A child's hospital admission for fever can incur significant financial costs for their family. One in five participating families reported financial hardship following their child's admission. Self-employed and single parents were disadvantaged by unplanned hospital admissions and at an increased risk of financial hardship. Local hospital policies should be improved to support families in the current financial climate.

The consumption of animal products is associated with plasma levels of alpha-aminoadipic acid (2-AAA).

BACKGROUND AND AIMS: The cardiometabolic disease-associated metabolite, alpha-aminoadipic acid (2-AAA) is formed from the breakdown of the essential dietary amino acid lysine. However, it was not known whether elevated plasma levels of 2-AAA are related to dietary nutrient intake. We aimed to determine whether diet is a determinant of circulating 2-AAA in healthy individuals, and whether 2-AAA is altered in response to dietary modification. METHODS AND RESULTS: We investigated the association between 2-AAA and dietary nutrient intake in a cross-sectional study of healthy individuals (N = 254). We then performed a randomized cross-over dietary intervention trial to investigate the effect of lysine supplementation (1 week) on 2-AAA in healthy individuals (N = 40). We further assessed the effect of a vegetarian diet on 2-AAA in a short-term (4-day) dietary intervention trial in healthy omnivorous women (N = 35). We found that self-reported dietary intake of animal products, including meat, poultry, and seafood, was associated with higher plasma 2-AAA cross-sectionally (P < 0.0001). Supplementary dietary lysine (5g/day) caused no significant increase in plasma 2-AAA; however, plasma 2-AAA was altered by general dietary modification. Further, plasma 2-AAA was significantly reduced by a short-term vegetarian diet (P = 0.003). CONCLUSION: We identified associations between plasma 2-AAA and consumption of animal products, which were validated in a vegetarian dietary intervention trial, but not in a trial designed to specifically increase the 2-AAA amino acid precursor lysine. Further studies are warranted to investigate whether implementation of a vegetarian diet improves cardiometabolic risk in individuals with elevated 2-AAA.

Open or robotic? Radical cystectomies for patients with non-metastatic bladder cancer: A systematic review and meta-analysis.

Background: This systematic review and meta-analysis will review randomized control trials for localized bladder cancer, evaluating surgical and pathologic outcomes of ORC versus RARC. Methods: Randomized studies evaluating adults with non-metastatic bladder cancer who underwent a radical cystectomy. Randomized trials were selected for final review. Data was extracted and analyzed with Revman 5 software. The primary outcome was complication rates within 90 days. Secondary outcomes included postoperative quality of life, estimated intraoperative blood loss, and other perioperative outcomes. Continuous variables were reported using mean difference with 95% confidence intervals, and dichotomous variables were reported using risk difference with 95% confidence intervals with RARC as the experimental group and ORC as the reference group. Results: Of 134 articles screened, six unique randomized studies were selected. For Grade I-II complications, the risk ratio (RR) was 0.92 (95% CI [0.79,1.08], p = 0.33), and for Grade III-V complications, RR 0.93 (95% CI [0.73,1.18], p = 0.59). RARC resulted in decreased blood loss (95% CI [-438.08, -158.44], p < 0.00001) and longer operative time (95% CI [55.23, 133.13], p < 0.00001). Quality of life using the EORTC-QLQ-30 global health score at 3 months post-op appeared to favor RARC with a mean difference of 4.46 points (95% CI [1.78, 7.15], p = 0.001). Pathologic outcomes neither statistically nor clinically favored one modality, as there was no significant difference between mean lymph node yield (p = 0.49), positive lymph nodes (p = 1.00), and positive surgical margins (p = 0.85) between the surgical modalities. Conclusions: Although one surgical modality is not overtly superior, the choice may be decided by mitigating individual operative risk factors like intraoperative blood loss, operative time, post-operative quality of life, as well as institutional costs and learning curve among surgeons.

The use of NADH anisotropy to investigate mitochondrial cristae alignment.

Life may be expressed as the flow of electrons, protons, and other ions, resulting in large potential difference. It is also highly photo-sensitive, as a large proportion of the redox capable molecules it relies on are chromophoric. It is thus suggestive that a key organelle in eukaryotes, the mitochondrion, constantly adapt their morphology as part of the homeostatic process. Studying unstained in vivo nano-scale structure in live cells is technically very challenging. One option is to study a central electron carrier in metabolism, reduced nicotinamide adenine dinucleotide (NADH), which is fluorescent and mostly located within mitochondria. Using one and two-photon absorption (340-360 nm and 730 nm, respectively), fluorescence lifetime imaging and anisotropy spectroscopy of NADH in solution and in live cells, we show that mitochondria do indeed appear to be aligned and exhibit high anisotropy (asymmetric directionality). Aqueous solution of NADH showed an anisotropy of ~ 0.20 compared to fluorescein or coumarin of < 0.1 and 0.04 in water respectively and as expected for small organic molecules. The anisotropy of NADH also increased further to 0.30 in the presence of proteins and 0.42 in glycerol (restricted environment) following two-photon excitation, suggesting more ordered structures. Two-photon NADH fluorescence imaging of Michigan Cancer Foundation-7 (MCF7) also showed strong anisotropy of 0.25 to 0.45. NADH has a quantum yield of fluorescence of 2% compared to more than 40% for photoionisation (electron generation), when exposed to light at 360 nm and below. The consequence of such highly ordered and directional NADH patterns with respect to electron ejection upon ultra-violet (UV) excitation could be very informative-especially in relation to ascertaining the extent of quantum effects in biology, including electron and photonic cascade, communication and modulation of effects such as spin and tunnelling.

Preoperative urine culture with contaminants is not associated with increased risk for urinary tract infection after ureteroscopic stone treatment.

PURPOSE: We aimed to assess whether the presence of contaminants in the pre-operative urine culture (preop-UC) predicts postoperative urinary tract infection (postop-UTI) in patients undergoing elective ureteroscopy with laser lithotripsy. METHODS: A retrospective chart review was performed from 01/2019 to 12/2021 examining patients with unilateral stone burden ≤ 2 cm who underwent ureteroscopy with laser lithotripsy and had a preop-UC within 3 months. Positive, negative, contaminated, and polymicrobial definitions for UCs were established in accordance with current guidelines. Patients with positive and polymicrobial cultures were excluded. Postop-UTI was defined as the presence of urinary symptoms and a positive UC within 30 days of the procedure. Multivariable logistic regression models were utilized to evaluate risk factors for contamination in the preop-UC and the risk of postop-UTI. RESULTS: A total of 201 patients met the inclusion-exclusion criteria. Preop-UC was negative in 153 patients and contaminated in 48 patients. Significant contaminant-related factors included female gender and increased BMI. Postop-UTI was diagnosed in 3.2% of patients with negative preop-UCs and 4.2% of patients with contaminants, with no difference between groups (p = 0.67). The regression model determined that the presence of contaminants in preop-UC failed to predict postop-UTI (OR 0.69, p = 0.64). CONCLUSION: The presence of contaminants in preop-UCs is not associated with an increased risk of postop-UTIs after ureteroscopy. Our study supports that contaminants in the preop-UC can be interpreted as a negative UC in terms of postop-UTI risk stratification. Preoperative antibiotics should not be prescribed for patients undergoing uncomplicated ureteroscopy for stone surgery in the setting of a contaminated preop-UC.

Development of a Universal Advanced Practice Provider Fellowship: A Roadmap to Increase Program Accessibility and Financial Sustainability.

Advanced practice providers (APPs) are a growing and essential component of today's health care delivery models. APP fellowship programs have been developed by health care systems to address APP recruitment, retention, and preparedness. However, APP fellowship programs are not widely accessible to most new graduate APPs or experienced APPs who wish to change their specialty. The development of these programs can be costly for health care systems to initiate and maintain. This article discusses the development of a "universal" APP fellowship program that allows for increased program accessibility and financial sustainability for health care systems. [J Contin Educ Nurs. 2024;55(1):4-6.].

Impact of Renal Access Angle and Speed of Nephroscope Retrieval Movements on the Vortex Effect.

OBJECTIVE: To analyze the influence of different renal access angles (AAs) and nephroscope retrieval speeds on the efficacy of the vortex effect (VE) in mini-percutaneous nephrolithotomy (mini-PCNL). This study aimed to understand the poorly understood physical components of the VE. MATERIALS AND METHODS: A Pexiglas™ (KUS®) model was built based on the dimensions of a 15/16 F mini-PCNL set (Karl Storz). The flow rate was continuous via an automatic pump and calibrated to achieve hydrodynamic equivalence to the real equipment. One experiment consisted of manually retrieving all 30 stone phantoms (3 mm diameter) utilizing only the VE. Cumulative time to retrieve all stones was measured. An accelerometer recorded instant speeds of the nephroscope every 0.08 seconds (s), and 3 experiments were performed at each angle (0°, 45°, and 90°). A logistic regression model was built utilizing maximum speeds and access angles to predict the effectiveness of the VE. RESULTS: Mean cumulative time for complete stone retrieval was 28.1 seconds at 0° vs 116.5 seconds at 45° vs 101.4 seconds at 90° (P < .01). We noted significantly higher speeds at 0° compared to 45° and 90° (P < .01); however, differences in average and maximum speed between 45° and 90° were not statistically significant (P = .21 and P = .25, respectively). The regression model demonstrated a negative association between increasing maximum speed and VE's effectiveness (OR 0.547, CI 95% 0.350-0.855, P < .01). When controlling for maximum speed, the 0° angle had significantly higher chances of achieving at least a partially effective VE. CONCLUSION: Increasing the renal access angle or nephroscope extraction speed negatively impacts the effectiveness of the VE. This significantly increased procedure time in the laboratory model, suggesting that the VE is less effective at higher sheath angles.

Battling the "Imposter": Our Experience in the Development of an Advance Practice Provider Fellowship.

In the face of ever-evolving shifts in health care, the demand for advanced practice providers (APPs), including nurse practitioners and physician assistants, continues to grow as the nation faces provider shortages and increased patient complexity. Because of different educational backgrounds and previous professional experience, there is a gap in readiness for practice following completion of academic programs, leading to high rates of turnover and financial implications for health care institutions. The creation of APP fellowship programs is a strategy many health institutions implement to provide enhanced support for new graduate APPs. These programs offer fully licensed and credentialed nurse practitioners and physician assistants additional experience within medical specialty areas. The establishment and operational cost associated with an APP fellowship program is a significant barrier health systems face. This article discusses how Saint Luke's Health System developed an APP fellowship program to address these barriers. The model addresses specific fellow needs and has contributed to improved employee retention rates, increased clinical competency, and overall provider satisfaction within Saint Luke's Health System. The evolution of the model, successes, barriers, and opportunities for future program growth are discussed within this article.

Aortic arch endovascular branch and fenestrated repair: Initial Canadian experience with novel technology.

Objective: The objective is to describe the initial Canadian experience using novel aortic arch branched endograft technologies. Methods: We performed a retrospective consecutive case series of all patients undergoing aortic arch branched repair with newly available endograft technology since 2020 at our site. We describe the patient characteristics, treatment characteristics, and postoperative outcomes. Results: Eleven patients received arch branched endografts, indicated for penetrating aortic ulcer in seven patients (64%), arch degeneration after prior aortic dissection repair in three (27%), and acute aortobronchial fistula in one patient (9%). Their average age was 72 ± 7 years. Complete arch repair from zone 0 to 4 was performed in six cases (55%); the remaining repairs landed proximally in zones 1 or 2. Seven repairs used a single retrograde facing inner branch (thoracic branch endoprosthesis; W.L. Gore & Associates), three used double antegrade inner branch (Bolton Relay; Terumo Interventional Systems), and one emergent case used double in situ fenestrations. Seven repairs (64%) used an adjunctive extra-anatomic bypass to complete great vessel perfusion, two of which were created during a prior aortic repair. Inferior vena cava balloon inflow occlusion during deployment was used in all cases. No mortalities, transient or permanent spinal cord paralysis, myocardial infarction, dialysis dependence, venous thromboembolism, or bleeding requiring reintervention occurred. No patient undergoing elective arch branch repair experienced a stroke. The one patient undergoing emergent repair did suffer a stroke. The median length of stay was 5 days (interquartile range, 2-8 days). Two endoleaks developed: a type Ia endoleak successfully treated with a Palmaz stent (Cordis) during the index admission, and a type II endoleak with ongoing sac regression on postoperative follow-up. Postoperatively, one patient suffered a suspected aortic graft infection that was treated with lifelong antibiotics. During a mean radiographic follow-up of 7.2 months, no cases of branch vessel instability (ie, no migration, reintervention, arterial rupture, intraluminal thrombus, occlusion, stenosis, or kinking of the branch grafts) developed. Three patients experienced sac regression of >5 mm, and no patient experienced continued postoperative dilation. Conclusions: To the best of our knowledge, this is the largest reported Canadian volume of aortic arch repair using novel branched or fenestrated technology. The series demonstrates that a multidisciplinary program and properly selected patients can yield excellent results using endovascular repair for complex aortic arch pathology.

Association of alpha-aminoadipic acid with cardiometabolic risk factors in healthy and high-risk individuals.

Introduction: Plasma levels of the metabolite alpha-aminoadipic acid (2-AAA) have been associated with risk of type 2 diabetes (T2D) and atherosclerosis. However, little is known about the relationship of 2-AAA to other cardiometabolic risk markers in pre-disease states, or in the setting of comorbid disease. Methods: We measured circulating 2-AAA using two methods in 1) a sample of 261 healthy individuals (2-AAA Study), and 2) in a sample of 134 persons comprising 110 individuals with treated HIV, with or without T2D, a population at high risk of metabolic disease and cardiovascular events despite suppression of circulating virus, and 24 individuals with T2D without HIV (HATIM Study). We examined associations between plasma 2-AAA and markers of cardiometabolic health within each cohort. Results and discussion: We observed differences in 2-AAA by sex and race in both cohorts, with higher levels observed in men compared with women, and in Asian compared with Black or white individuals (P<0.05). There was no significant difference in 2-AAA by HIV status within individuals with T2D in the HATIM Study. We confirmed associations between 2-AAA and dyslipidemia in both cohorts, where high 2-AAA associated with low HDL cholesterol (P<0.001) and high triglycerides (P<0.05). As expected, within the cohort of people with HIV, 2-AAA was higher in the setting of T2D compared to pre-diabetes or normoglycemia (P<0.001). 2-AAA was positively associated with body mass index (BMI) in the 2-AAA Study, and with waist circumference and measures of visceral fat volume in HATIM (all P<0.05). Further, 2-AAA associated with increased liver fat in persons with HIV (P<0.001). Our study confirms 2-AAA as a marker of cardiometabolic risk in both healthy individuals and those at high cardiometabolic risk, reveals relationships with adiposity and hepatic steatosis, and highlights important differences by sex and race. Further studies are warranted to establish molecular mechanisms linking 2-AAA to disease in other high-risk populations.

Predictive factors for treatment response and mortality in chronic pulmonary aspergillosis.

OBJECTIVES: Chronic pulmonary aspergillosis (CPA) is associated with significant mortality, and suboptimal antifungal treatment response. We describe predictive factors for treatment response and survival. METHODS: We retrospectively analysed clinical, serological and radiological parameters at baseline and following antifungal treatment in patients with CPA and correlated with clinical and radiological response and survival. RESULTS: Fifty-nine patients were included with a mean age of 61 years. Thirty (51%) had a diagnosis of COPD. On clinical assessment at 6 months, 21 (36%) had clinically improved, 20 (34%) were clinically stable and 15 (25%) had deteriorated. Radiological improvement was observed in 30 (53%), stability in 11 (19%) and deterioration in 16 (28%). Only a lower C-reactive protein (CRP) at baseline was associated with a favourable clinical-radiological response. On univariate analysis, lower CRP, higher albumin, lower Aspergillus IgG and use of inhaled steroids were associated with lower mortality. An overall favourable response at 6 months was associated with lower mortality. CONCLUSION: Inflammatory markers and Aspergillus IgG were predictors of mortality in CPA. This suggests that mortality in CPA is driven mainly by the chronic fungal infection itself rather than the underlying disease, therefore early optimised treatment of CPA may lead to improved outcomes.

Association of alpha-aminoadipic acid (2-AAA) with cardiometabolic risk factors in healthy and high-risk individuals.

Plasma levels of the metabolite alpha-aminoadipic acid (2-AAA) have been associated with risk of type 2 diabetes (T2D) and atherosclerosis. However, little is known about the relationship of 2-AAA to other cardiometabolic risk markers in pre-disease states, or in the setting of comorbid disease. We measured circulating 2-AAA using two methods in 1) a sample of 261 healthy individuals (2-AAA Study), and 2) in a sample of 134 persons comprising 110 individuals with treated HIV, with or without T2D, a population at high risk of metabolic disease and cardiovascular events despite suppression of circulating virus, and 24 individuals with T2D without HIV (HATIM Study). We examined associations between plasma 2-AAA and markers of cardiometabolic health within each cohort. We observed differences in 2-AAA by sex and race in both cohorts, with higher levels observed in men compared with women, and in Asian compared with Black or white individuals (P<0.05). There was no significant difference in 2-AAA by HIV status within individuals with T2D in the HATIM Study. We confirmed associations between 2-AAA and dyslipidemia in both cohorts where high 2-AAA associated with low HDL cholesterol (P<0.001) and high triglycerides (P<0.05). As expected, within the cohort of people with HIV, 2-AAA was higher in the setting of T2D compared to pre-diabetes or normoglycemia (P<0.001). 2-AAA was positively associated with body mass index (BMI) in the 2-AAA Study, and with waist circumference and measures of visceral fat volume in HATIM (all P<0.05). Further, 2-AAA associated with increased liver fat in persons with HIV (P<0.001). Our study confirms 2-AAA as a marker of cardiometabolic risk in both healthy individuals and those at high cardiometabolic risk, reveals relationships with adiposity and hepatic steatosis, and highlights important differences by sex and race. Further studies are warranted to establish molecular mechanisms linking 2-AAA to disease in other high-risk populations.

Sphingopyxis Species Isolated from Sand Filter Biofilm at an Australian Drinking Water Treatment Works.

Three strains isolated by geosmin enrichment from a sand filter in an Australian drinking water treatment works were genome sequenced to identify their taxonomic placement, and a bench-scale batch experiment confirmed their geosmin-degrading capability. Using the average nucleotide identity based on the MUMmer algorithm (ANIm), pairwise digital DNA-DNA hybridization (dDDH), and phylogenomic analyses, the strains were identified as Sphingopyxis species.

IP3 receptors: An "elementary" journey from structure to signals.

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are large tetrameric channels which sit mostly in the membrane of the endoplasmic reticulum (ER) and mediate Ca2+ release from intracellular stores in response to extracellular stimuli in almost all cells. Dual regulation of IP3Rs by IP3 and Ca2+ itself, upstream "licensing", and the arrangement of IP3Rs into small clusters in the ER membrane, allow IP3Rs to generate spatially and temporally diverse Ca2+ signals. The characteristic biphasic regulation of IP3Rs by cytosolic Ca2+ concentration underpins regenerative Ca2+ signals by Ca2+-induced Ca2+-release, while also preventing uncontrolled explosive Ca2+ release. In this way, cells can harness a simple ion such as Ca2+ as a near-universal intracellular messenger to regulate diverse cellular functions, including those with conflicting outcomes such as cell survival and cell death. High-resolution structures of the IP3R bound to IP3 and Ca2+ in different combinations have together started to unravel the workings of this giant channel. Here we discuss, in the context of recently published structures, how the tight regulation of IP3Rs and their cellular geography lead to generation of "elementary" local Ca2+ signals known as Ca2+ "puffs", which form the fundamental bottleneck through which all IP3-mediated cytosolic Ca2+ signals must first pass.