Spontaneous Reduction Research Articles

Emergent tetragonality in a fundamentally orthorhombic material.

Symmetry plays a key role in determining the physical properties of materials. By Neumann's principle, the properties of a material remain invariant under the symmetry operations of the space group to which the material belongs. Continuous phase transitions are associated with a spontaneous reduction in symmetry. Less common are examples where proximity to a continuous phase transition leads to an increase in symmetry. We find signatures of an emergent tetragonal symmetry close to a charge density wave (CDW) bicritical point in a fundamentally orthorhombic material, ErTe3, for which the two distinct CDW phase transitions are tuned via anisotropic strain. We first establish that tension along the a axis favors an abrupt rotation of the CDW wave vector from the c to a axis and infer the presence of a bicritical point where the two continuous phase transitions meet. We then observe a divergence of the nematic elastoresistivity approaching this putative bicritical point, indicating an emergent tetragonality in the critical behavior.

Adsorption induced bipolar excitation at semiconductor surface

Adsorption on metal surfaces has been shown to lead to chemisorption induced electronic excitation but direct experimental evidence of chemisorption induced excitation on semiconductor surfaces is still missing. Here, we design and use high-quality Silicon (Si) p-n diodes to in-situ probe the charge transfer process taking place during vapor and liquid phase chemisorption of iodine molecules on H-Si (100) surface. We find that the diodes can generate electricity and feed an external circuit during the chemisorption process, demonstrating chemisorption-induced electron and hole generation and the means to electrically monitor the process. A bipolar semiconductor electrochemical model where a single semiconductor surface hosts the spontaneous oxidation (electron injection) and reduction (hole injection) reactions simultaneously on its conduction and valence bands without any electrolytes is proposed to explain the observations. Our work provides new insight on the energy relaxation processes of chemisorption and also calls for further studies on the observed chemovoltaic effect. Overall, the results indicate a possibility for developing electrolyte-free vapor phase chemical energy-to-electricity converters and detectors.

Sacrococcygeal chordoma with spontaneous regression due to a large hemorrhagic component

Chordoma is a malignant bone tumor originating from notochordal remnants, most commonly occurring at the sacrococcygeal junction. We present a case of a 70-year-old male with chronic pain in the lower lumbar spine. MRI performed elsewhere revealed a large tumor that involved S4, S5, and the coccyx with a presacral soft tissue component. The lesion was heterogeneously hyperintense on T2-weighted images with a thick hypointense rim anteriorly. On T1-weighted images, the lesion showed a native hyperintense signal centrally probably due to hemorrhage. Based on this MRI, the diagnosis of chordoma was suggested. A spontaneous marked reduction in size was observed on a 4-week interval MRI performed at our institution before biopsy. Due to spontaneous tumor shrinkage along with peripheral enhancement, a differential diagnosis of infection or bleeding in a retrorectal cyst was proposed. This case teaches us that chordomas may contain a large hemorrhagic component, which is hyperintense on T1-weighted images and shows peripheral rim enhancement. Spontaneous shrinkage of a tumor may occur due to the resolution of a hematoma within weeks. Biopsy is key to obtain the correct diagnosis. Understanding the typical and more rare features of chordomas is key for MSK radiologists as well as pathologists. Chordomas are typically slow-growing tumors, but radiologists should be aware that intratumoral hemorrhage can lead to rapid changes in tumor size, which may be mistaken for either regression or progression of tumor. This case highlights the importance of considering hemorrhagic events within chordomas in the differential diagnosis when observing size fluctuations on imaging.

Flexible Copper Films Modification via Spontaneous Reduction of Aryldiazonium Gold Salts: Unraveling Surface Properties and Energy Profile.

In this study, we report the modification of flexible copper films via the spontaneous reduction of aryldiazonium gold salts [X-4-C6H4N≡N]AuCl4 (X═COOH, NO2). The electroless modification involves dipping of flexible copper films in the aryldiazonium gold solutions for a few seconds, under ambient conditions, followed by a washing step with deionized water to obtain a mechanically robust gold-aryl coating. The chemical composition, morphology, electronic structure, and optical properties of the gold-aryl layer and the flexibility of the modified copper films are supported by the results from X-ray photoelectron spectroscopy (XPS), electrochemistry, contact angle, scanning electron microscopy (SEM), and ultraviolet photoelectron spectroscopy (UPS). XPS surface analysis showed metallic gold in addition to C-C, C-O/C-N, and C═O functional groups from the grafted aryls. Cu 2p showed metallic copper as a major component and a small amount of Cu(II) ions. Wettability studies showed that Au-COOH@Cu increased the contact angle of the bare copper films from 68.0 ± 0.7° to 82.0° ± 0.7°, while Au-NO2@Cu increased the contact angle to 134.0° ± 0.3°. UPS energy profile analysis of [HOOC-4-C6H4N≡N]AuCl4 (valence band maximum = 1.91 eV) exhibited greater reducibility than [O2N-4-C6H4N≡N]AuCl4 (valence band maximum = 2.91 eV). The lower ionization potential of [HOOC-4-C6H4N≡N]AuCl4 (IP = 4.33 eV) enhanced the reactivity upon copper film contact, potentially inducing efficient energy level alignment, compared with [O2N-4-C6H4N≡N]AuCl4 (IP = 5.62 eV). UPS results were further supported by electrochemistry investigation which revealed that [HOOC-4-C6H4N≡N]AuCl4 is easily reducible compared with [O2N-4-C6H4N≡N]AuCl4. The findings presented here hold significant implications for developing flexible copper films and pave the way for future advancements in electronic material modification for industrial applications.

Designer "Quasi-Benzyne": The Spontaneous Reduction of Ortho-Diiodotetrafluorobenzene on Water Microdroplets.

It has been widely shown that water microdroplets have a plethora of unique properties that are highly distinct from those of bulk water, among which an especially intriguing one is the strong reducing power as a result of the electrons spontaneously generated at the air-water interface. In this study, we take advantage of the reducing power of water microdroplets to reduce ortho-diiodotetrafluorobenzene (o-C6F4I2) into a C6F4I2•- radical anion. Photoelectron spectroscopy and density functional theory computations reveal that the excess electron in C6F4I2•- occupies the I-C1-C2-I linkage, which elongates the C-I bonds but surprisingly shortens the C1-C2 bond, making the bond order higher than a double bond, similar to the benzyne molecule, so we named it "quasi-benzyne". The C6F4I2•- anion was further successfully utilized in a Diels-Alder reaction, a typical reaction for benzyne. This study provides a good example of strategically utilizing the spontaneous properties of water microdroplets and generating an especially exotic anion, and we anticipate that microdroplet chemistry can be an avenue rich in opportunities for new catalyst-free organic reactions.

The decline of the 2022 Italian mpox epidemic: Role of behavior changes and control strategies

In 2022, a global outbreak of mpox occurred, predominantly impacting men who have sex with men (MSM). The rapid decline of this epidemic is yet to be fully understood. We investigated the Italian outbreak by means of an individual-based mathematical model calibrated to surveillance data. The model accounts for transmission within the MSM sexual contact network, in recreational and sex clubs attended by MSM, and in households. We indicate a strong spontaneous reduction in sexual transmission (61-87%) in affected MSM communities as the possible driving factor for the rapid decline in cases. The MSM sexual contact network was the main responsible for transmission (about 80%), with clubs and households contributing residually. Contact tracing prevented about half of the potential cases, and a higher success rate in tracing contacts could significantly amplify its effectiveness. Notably, immunizing the 23% of MSM with the highest sexual activity (10 or more partners per year) could completely prevent new mpox resurgences. This research underscores the importance of augmenting contact tracing, targeted immunization campaigns of high-risk groups, and fostering reactive behavioral changes as key strategies to manage and prevent the spread of emerging sexually transmitted pathogens like mpox within the MSM community.

The PIVOT App: A User Guide

Background: While the pivot shift examination is often regarded as the gold standard test for diagnosis of anterior cruciate ligament (ACL) injury, one of the pitfalls of the pivot shift test is that it lacks standardization among physicians. The PIVOT App is a validated application to quantify the amount of tibial translation during the pivot shift maneuver and improve standardization of clinical measurement. Indications: The PIVOT App can be used in both clinic and operating room settings for patients who sustained injury to the ACL. The PIVOT App may assist in identifying the amount of rotatory knee laxity in patients with ACL deficiency or following ACL reconstruction. Technique Description: The PIVOT App works by quantifying the amount of translation in the lateral tibia relative to a marker on the lateral femoral epicondyle. To use the PIVOT App, 3 yellow circle stickers are placed on the bony prominences of the lateral knee: the lateral epicondyle, Gerdy’s tubercle, and the “pivot point” 3 cm posterior to Gerdy’s tubercle parallel to the joint line. Once placed, the pivot shift flexion maneuver can be recorded in the PIVOT App and analyzed to identify both the distance of spontaneous tibial reduction during the pivot shift maneuver and the time of reduction in seconds. The most common problems encountered while using the application include (1) improper marker placement, (2) interference of marker tracking with yellow color in the background, (3) interference of marker tracking with overhead lighting, and (4) extraneous data collection before and after pivot shift flexion. Results: Previous studies have validated the PIVOT App to accurately distinguish normal, low-grade, and high-grade pivot shifts with resultant increasing tibial translation in the lateral compartment of the knee. The PIVOT App has been used at institutions worldwide to quantify and standardize measurement of the pivot shift. Conclusion: The PIVOT App is a validated application to quantify the amount of lateral tibial translation and reduction during the pivot shift maneuver. Proper use and avoidance of complications while using the application can aid clinicians in accurate diagnosis of rotatory knee laxity in patients following ACL injury. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Tryptophanhydroxamic Acid-Stabilized Ultrasmall Gold Nanoclusters: Tuning the Selectivity for Metal Ion Sensing.

Sub-nanometer-sized gold nanoclusters (Au NCs) were prepared via the spontaneous reduction of [AuCl4]-- ions with a hydroxamate derivative of L-tryptophan (Trp) natural amino acid (TrpHA). The prepared TrpHA-Au NCs possess intense blue emission (λem = 470 nm; λex = 380 nm) with a 2.13% absolute quantum yield and 1.47 ns average lifetime. The Trp-stabilized noble metal NCs are excellent metal ion sensors for Fe3+, but in this work, we highlighted that the incorporation of the hydroxamate functional group with an excellent metal ion binding capability can tune the selectivity and sensitivity of these NCs, which is a promising way to design novel strategies for the detection of other metal ions as well. Moreover, their simultaneous identification can also be realized. By decreasing the sensitivity of our nano-sensor for Fe3+ (limit of detection (LOD) ~11 µM), it was clearly demonstrated that the selectivity for Cu2+-ions can be significantly increased (LOD = 3.16 µM) in an acidic (pH = 3-4) condition. The surface-bounded TrpHA molecules can coordinate the Cu2+ confirmed by thermodynamic data, which strongly generates the linking of the NCs via the Cu2+ ions in acidic pH, and a parallel fluorescence quenching occurs. In the case of Fe3+, the degree of quenching strongly depends on the metal ion concentration, and it only occurs when the NCs are not able to bind more Fe3+ (~10 µM) on the surface, causing the NCs' aggregation.

Organic Catalysis Promotor for Advanced Water Electrolysis

AbstractAchieving carbon neutrality necessitates large‐scale water electrolyzers for green hydrogen production. Accordingly, it is emphasized to develop promising catalyst candidates, which can simultaneously achieve high catalysis efficiency, environmental friendliness, and sustainability. Recently, 3d‐transition‐metal–based catalysts are proposed to replace noble‐metal–based catalysts, which have limited reserves and emit CO2 during their production; however, the limited catalytic performance of 3d‐transition‐metal–based catalysts introduces a tradeoff. Therefore, in this work, the authors focus on suggesting a breakthrough that can intrinsically enhance the catalysis efficiency by adopting a new component in water electrolysis system. Here, a novel concept of organic catalysis promotor (OCP), dissolved in the electrolyte as an additive, which accelerates the sluggish oxygen evolution reaction in alkaline‐based water electrolysis, currently the most mature technology, is proposed. OCP acts as a liquid‐phase cocatalyst, decreasing the activation energy of oxygen evolution reaction by spontaneous chemical reduction to extract an electron from the reaction intermediates. This innovative approach of adopting the OCP of the 2,2,6,6‐tetramethylpiperidine‐1‐oxyl series significantly decreases the overpotential and shows successful general applicability, offering a new rudder in shifting the energy paradigm toward carbon neutrality.

Interfacial Spontaneous Reduction Strategy to Synthesize Low-Valent Pt Single-Atom Catalyst for Boosting Hydrosilylation

Interfacial Spontaneous Reduction Strategy to Synthesize Low-Valent Pt Single-Atom Catalyst for Boosting Hydrosilylation

Ti3+ redox dynamics enabling efficient nitrate reduction to ammonia on Ti2O3

The electrochemical nitrate reduction reaction (NO3−RR) demonstrates significant promise as a sustainable pathway for ammonia (NH3) synthesis and regulating the Earth's nitrogen cycle. However, its advancement is currently hindered by low catalytic activity, particularly limited by the sluggish rate-determining step of NO2− formation. Herein, we capitalize on the highly active and versatile redox properties of Ti3+ in Ti2O3, exploiting its spontaneous reduction of NO3− to NO2− to overcome the sluggish rate-determining step. Subsequently, the electrochemical reduction process continuously reduces the generated high valence titanium species back to Ti3+, creating a redox closed loop, and enabling the continuous NH3 synthesis. The catalyst achieves an outstanding NH3 production rate of 19.04 mg h−1 mgcat.–1 with a Faradaic efficiency of 97.8 %. Using in-situ electrochemical electron paramagnetic resonance technology, we explored dynamic changes of Ti3+ in Ti2O3 during the process, while in-situ electrochemical infrared spectroscopy provided insights into intermediates' evolution. Density functional theory calculations confirmed Ti2O3′s highly active NO3−RR.

Synthesis of thermosensitive hybrid structure gold nanotriangles coated with poly(N-isopropylacrylamide) for reversible confinement of molecules

In this work, we investigate a synthesis method for novel systems that involve the use of gold nanotriangles arrays (AuNTs) coated with poly(N-isopropylacrylamide) (pNIPAM) brushes, designed as smart platforms for the reversible confinement of bio-particles. Initially, we employed cost-effective nanosphere lithography to fabricate gold nanotriangles arrays. Next, polymer initiator groups were attached to the AuNTs surface through a spontaneous reduction approach, enabling exclusive functionalization of pNIPAM on the gold surface. Finally, we utilized surface-initiated atom transfer radical polymerization to graft pNIPAM brushes onto the gold surface. We systematically investigated the polymer initiator groups’ grafting time and the polymerization time to control the thickness of the grafted pNIPAM brushes. Subsequently, we characterized the thermoresponsive properties of these hybrid structures using Atomic Force Microscopy (AFM) measurements, evaluating their ability to undergo on/off adsorption and desorption of polystyrene (PS) beads on their surface. Indeed, the combination of the thermosensitive pNIPAM polymer with AuNTs arrays results in the development of a precisely regulated two-dimensional active device which exhibits tunable properties with external temperature changes, making it a versatile platform suitable for a wide range of applications.

Eternal inflation and collapse theories

The eternal inflation problem continues to be considered one of standard's cosmology most serious shortcomings. This arises when one considers the effects of “quantum fluctuations” on the zero mode of inflaton field during a Hubble time in the inflationary epoch.In the slow-roll regime it is quite clear that such quantum fluctuations could dwarf the classical rolling down of the inflaton, and with overwhelming probability this prevents inflation from ever ending. When one recognizes that quantum fluctuations can not be taken as synonymous of stochastic fluctuations, but rather intrinsic levels of indefiniteness in the quantities in question, one concludes that the eternal inflation problem simply does not exist. However, the same argument would serve to invalidate the account for the generation of the primordial seeds of cosmic structure as has been amply discussed elsewhere [1,2,3]. In order to do address that issue, one must explain the breaking of homogeneity and isotropy of the situation prevailing during the early inflationary epoch (at both the quantum and classical levels of the description). For that one needs to rely on some additional element, beyond those present in the traditional treatments. The so called spontaneous collapse theories offer a viable candidate for that element, namely the stochastic and spontaneous state reduction characteristic of those proposals possesses the basic features to break those symmetries. In fact, a version of the CSL theory adapted to the cosmological context has been shown to offer a satisfactory account for the origin the seeds of cosmic structure with an adequate power spectrum [2], and will serve as the basis of our analysis. However, once such stochastic collapse is introduced into the theoretical framework the eternal inflation problem has the potential reappear.In this manuscript we explore those issues in detail and discuss an avenue that seems to allow for a satisfactory account for the generation of the primordial inhomogeneities and anisotropies while freeing the theory from the eternal inflation problem.

Why do some metal ions spontaneously form nanoparticles in water microdroplets? Disentangling the contributions of the air-water interface and bulk redox chemistry.

Water microdroplets containing 100 μM HAuCl4 have been shown to reduce gold ions into gold nanoparticles spontaneously. It has been suggested that this chemical transformation takes place exclusively at the air-water interface of microdroplets, albeit without mechanistic insights. We compared the fate of several metallic salts in water, methanol, ethanol, and acetonitrile in the bulk phase and microdroplet geometry (sprays). Experiments revealed that when HAuCl4 (or PtCl4) is added to bulk water (or methanol or ethanol), metal NPs appear spontaneously. Over time, the nanoparticles grow, evidenced by the bulk solutions' changing colors. If the bulk solution is sprayed pneumatically and microdroplets are collected, the NP size distribution is not significantly enhanced. We find that the reduction of metal ions is accompanied by the oxidation of water (or alcohols); however, these redox reactions are minimal in acetonitrile. This establishes that the spontaneous reduction of metal ions is (i) a bulk phase phenomenon in water and several non-aqueous solutions, (ii) minimally affected by the air-water interface or the microdroplet geometry, and (iii) is not limited to Au3+ ions and can be explained via the electrochemical series. These results advance our understanding of aquatic chemistry and liquids in general and should be relevant in soil chemistry, biogeochemistry, electrochemistry, and green chemistry.

A Case of Osteofibrous Dysplasia at Birth: 2-Year Follow-Up

Osteofibrous dysplasia (OFD) is characterized by excessive resorption of long bone, especially tibia, with subsequent fibrous repair of the defect. OFD is an uncommon benign tumor of young children – neonatal presentation is restricted to single digits in literature. We describe a rare case of OFD in a newborn, which presented as unilateral painless lower limb deformity at birth. Radiological findings were suggestive and biopsy was diagnostic of OFD. Postbiopsy, the patient underwent expectant management given the generally slow progression of this condition, the possibility of postbiopsy regression, and the known risk of recurrence after surgical intervention. By 13 months, the lesion had undergone complete radiological resolution with spontaneous reduction of deformity. There has been no recurrence of disease at the same or another site till now (24 months age). There is no limb length discrepancy and motor milestones are appropriate for age; nevertheless, follow-up till puberty has been advised.

Is TAPP the Right alternative for patients undergoing emergency surgery for incarcerated inguinal hernia?

Incarcerated inguinal hernia requires emergency intervention.The incarcerated segment should be thoroughly inspected in order to evaluate the degree of ischemia and decide whether resection is required.The aim of this study is to evaluate the applicability of TAPP for patients seen in the emergency department for incarcerated inguinal hernias. The study was done retrospectively.Patients who presented to the emergency department and were operated with the TAPP technique were included.İn all patients laparoscopic abdominal exploration was done to determine the extent of the incarcerated intestinal segment and evaluate the need for resection.TAPP technique was used to laparoscopically repair the hernia. The demographics of the patients,technique used for the hernia repair,necessity for resection,postoperative mortality and morbidity and recurrence rates were recorded. 109 patients were seen for incarcerated hernia.12 patients were excluded either because they were not suitable for or did not consent to laparoscopic repair.97 patients had hernia repair with TAPP technique.İn 6 patients spontaneous reduction of the incarcerated segment was observed after anesthesia induction.İn 9 patients necrosis of the incarcerated segment was observed and re-section and anostomosis was performed.7 patients had laparoscopic 2 patients had open resections.Seroma was observed in 7, hema-toma in 3 and wound infection in 2 patients postoperatively.No mortality was seen.1 patient had a recurrence in the follow up period. TAPP technique is a good alternative for selected patients undergoing emergency hernia repair because it provides the surgeon with the possibility to evaluate the incarcerated intestinal segment thoroughly while preserving the advantages of laparoscopic surgery.

Design opto-thermo-mechano-multi-responsive luminescence from Sr4Al14O25: Eu2+, Nd3+, Tm3+ for optical information storage

The differences in the luminescent performance of phosphors determine their application in diverse occasions. However, the development of Eu2+ ion doped phosphors materials with high optical properties is not satisfactory due to the harsh synthesis conditions. Herein, a series of Sr4Al14O25: Eu2+, Nd3+, Tm3+ are constructed by high temperature solid reaction without applying reducing gas and protective gas. The charge mismatch caused by the unequal substitution promotes the spontaneous reduction of Eu3+ ions to Eu2+. Nd3+ and Tm3+ are co-doped into Sr4Al14O25: Eu2+ to regulate the trap structure, and photoluminescence, long persistent luminescence, photo-stimulated luminescence and mechanoluminescence of Eu2+ ions are simultaneously achieved in Sr4Al14O25: Eu2+, Nd3+, Tm3+. The relationship between trap and optical performance is explored in detail, and the temperature effect during mechanoluminescence is demonstrated for the first time. This research provides a new idea for the rapid synthesis of highly optical performance Eu2+-doped phosphors in air.

Facile synthesis of solar active charcoal passivated Ag3PO4 and their two-channel mechanisms for H2O2 formation in aerated water

This work presents the use of activated charcoal passivated-Ag3PO4 (CAgP) and bare Ag3PO4(AgP) nanoparticles (NPs) as effective photocatalysts for the generation of hydrogen peroxide (H2O2) in air-saturated water containing either formic acid (FA) or silver nitrate (AgNO3). The synthesized CAgP and pristine AgP were characterized using various state-of-the-art optical and electron microscopy techniques. The CAgP composites showed remarkable photocatalyzed H2O2 formation compared to bare AgP NPs. The CAgP photocatalyzed-assisted H2O2 formation from O2-saturated water under sunlight was achieved via two-channel mechanisms. First, in the presence of FA as a hole scavenger, enhanced H2O2 formation was facilitated by the decomposition of FA to produce proton (H+), followed by a spontaneous reduction of dissolved molecular oxygen by the valence band electrons. The second pathway involves the formation of H2O2 in the absence of electrons (using AgNO3 as an electron scavenger) which occurs via the oxidation of H2O by photo-induced holes to generate hydroxyl radicals (•HO) and the combination of •HO radicals to produce H2O2. The most notable feature of CAgP composite as a photocatalyst is the ease of H2O2 formation in O2/H2O and O2/H2O/FA system, as well as the ability to reuse the recovered CAgP catalyst for a few reaction cycles without losing substantial catalytic activity or mass.

Adsorption characteristics of SO2 onto novel activated carbon fixed bed: kinetics, isotherms, thermodynamics and washing regeneration

ABSTRACT The problem of SO2 pollution in industrial flue gas has brought great pressure to environmental governance. In this study, a new type of activated carbon fixed bed device was designed and built for flue gas desulfurization. The results showed that activated carbons (AC1-AC5) were microporous activated carbons with abundant functional groups on the surface, and the desulfurization performance was ranked as AC1 > AC2 > AC3 > AC4 > AC5. The specific surface area of AC1 was as high as 624.98 m2/g, and the maximum adsorption capacity was 29.03 mg·g−1 under the optimum reaction conditions. The Freundlich adsorption isotherm model and Bangham pore diffusion model are more suitable for describing the dynamic adsorption process of SO2 on AC1. Combined with thermodynamic research, it is shown that the adsorption process of SO2 is a spontaneous, exothermic, and chaotic reduction process, which is mainly a physical adsorption between single-layer adsorption and multi-layer adsorption. Finally, the desulfurization-washing regeneration cycle experiment results showed that the regeneration rate of AC1 increases with the washing time and washing temperature, up to 95%, which provides data reference for industrial application.

Correlates of Spontaneous Blood Pressure Reduction Following Severe Inpatient Hypertension Development.

Severe hypertension (sHTN) is prevalent in 10% of hospitalized patients and treatment guidelines are lacking. As such, patients who develop sHTN might unnecessarily receive antihypertensive medications which could lead to worse outcomes. Our goal was to investigate correlates of spontaneous blood pressure (BP) reduction to help guide future treatment decisions and avoid harm associated with aggressive BP treatment. This is a retrospective cohort study of hospitalized adults between 2016 and 2020 who developed sHTN, SBP >180 or DBP >110 mm Hg, after admission. Spontaneous BP reduction was defined as a SBP <160 and a DBP <100 mm Hg achieved within 3 h of sHTN in the absence of antihypertensive therapy. Multivariable logistic regression was used to identify correlates of spontaneous BP reduction. Of the 12,825 patients who developed sHTN, 44.2% had spontaneous BP reduction. After adjustment, we found that patients most likely to experience a BP drop received steroids before onset of sHTN (Odds ratio [OR]: 1.3 [1.09, 1.56]), had higher potassium levels on admission (OR: 1.2 [1.09, 1.24]) and were more likely to have a history of chronic pulmonary disease (OR: 1.1 [1.01, 1.18]) or cardiac arrythmia (OR: 1.1 [1.01, 1.18]). While numerically different, these differences were not clinically relevant. Our findings indicate that almost half the patients who develop sHTN have spontaneous BP reduction. Conventional clinical and demographic characteristics were not strong predictors of spontaneous BP reduction following sHTN development. More research is needed to confirm our findings and help guide treatment of sHTN.