Strain-Driven Solid-Solid Crystal Conversion in Chiral Hybrid Pseudo-Perovskites with Paramagnetic-to-Ferromagnetic Transition.

Hybrid organic-inorganic perovskites (HOIPs) are promising stimuli-responsive materials (SPMs) owing to their molecular softness and tailorable structural dimensionality. The design of mechanically responsive HOIPs requires an in-depth understanding of how lattice strain induces intermolecular rearrangement that impacts physical properties. While chirality transfer from an organic cation to an inorganic lattice is known to influence chiral-optical properties, its effect on strain-induced phase conversion has not been explored. As opposed to achiral or racemic organic cations, chiral organic cations can potentially afford a new dimension in strain-responsive structural change. Herein, we demonstrate that mechanical strain induces a solid phase crystal conversion in chiral halide pseudo-perovskite single crystals (R/S)-(FE)2CuCl4 (FE = (4-Fluorophenyl)ethylamine) from a 0D isolated CuCl4 tetrahedral to 1D corner-sharing CuFCl5 octahedral framework via the incorporation of Cu···F interaction and N-H···F hydrogen bonding. This strain-induced crystal-to-crystal conversion involves the connection of neighboring 0D CuCl4 tetrahedra via Cu2+-Cl--Cu2+ linkages as well as the incorporation of a F-terminated organic cation as one of the X atoms in BX6 octahedra, leading to a reduced band gap and paramagnetic-to-ferromagnetic conversion. Control experiments using nonchiral or racemic perovskite analogs show the absence of such solid phase conversion. To demonstrate pressure-sensitive properties, the 0D phase is dispersed in water-soluble poly(vinyl alcohol) (PVA) polymer, which can be applied to a large-scale pressure-induced array display on fibrous Spandex substrates via a screen-printing method.

Electron Spin Decoherence Dynamics in Magnetic Manganese Hybrid Organic-Inorganic Crystals: The Effect of Lattice Dimensionality.

Organic-inorganic metal hybrids with their tailorable lattice dimensionality and intrinsic spin-splitting properties are interesting material platforms for spintronic applications. While the spin decoherence process is extensively studied in lead- and tin-based hybrids, these systems generally show short spin decoherence lifetimes, and their correlation with the lattice framework is still not well-understood. Herein, we synthesized magnetic manganese hybrid single crystals of (4-fluorobenzylamine)2MnCl4, ((R)-3-fluoropyrrolidinium)MnCl3, and (pyrrolidinium)2MnCl4, which represent a change in lattice dimensionality from 2D and 1D to 0D, and studied their spin decoherence processes using continuous-wave electron spin resonance spectroscopy. All manganese hybrids exhibit nanosecond-scale spin decoherence time τ2 dominated by the symmetry-directed spin exchange interaction strengths of Mn2+-Mn2+ pairs, which is much longer than lead- and tin-based metal hybrids. In contrast to the similar temperature variation laws of τ2 in 2D and 0D structures, which first increase and gradually drop afterward, the 1D structure presents a monotonous rise of τ2 with the temperatures, indicating the strong correlation of spin decoherence with the lattice rigidity of the inorganic framework. This is also rationalized on the basis that the spin decoherence is governed by the competitive contributions from motional narrowing (prolonging the τ2) and electron-phonon coupling interaction (shortening the τ2), both of which are thermally activated, with the difference that the former is more pronounced in rigid crystalline lattices.

Phasicity and resistance of the arterial spectral Doppler waveform in a canine femoral focal artery stenosis model.

INTRODUCTION: This study aims to evaluate changes in the arterial spectral Doppler waveform in a canine artery stenosis model. METHODS: Canine femoral artery stenosis models were established in 12 beagle dogs. Doppler waveforms were recorded in the femoral artery preoperatively and postoperatively in the femoral artery and at the ankle after formation of a 50%, 70%, and 90% stenosis or occlusion. Major descriptors for arterial Doppler waveform were used to analyse waveforms. RESULTS: The proportion of multiphasic waveforms proximal to a moderate stenosis decreased compared to normal baseline, although the difference was not statistically significant, whereas the decreases at the stenosis, distal to the stenosis, and at the ankle were significant (p < 0.05). The decreases in arteries with a more severe stenosis or occlusion were significant at all locations (p < 0.05). The proportion of high resistive waveforms decreased significantly at the ankle in the arteries with a moderate stenosis (50%) (p = 0.002), but the decreases proximal to, at, and distal to the stenosis were not significant. The decreases were significant at all locations in the arteries with a more severe stenosis (p < 0.05). The decrease was significant at the ankle in the arteries with an occlusion (p < 0.001) but not significant pre, at, and post an occlusion. CONCLUSIONS: Phasicity and resistance of Doppler waveforms alter in canine femoral arteries with a stenosis. Phasicity change seems more sensitive in response to an arterial stenosis than resistance change. Additional information on arterial resistance could be obtained using end-diastolic ratios, resistive indices, and potentially end-systolic notch velocity measurements.

Value Of Anteroposterior-To-Transverse Ratio in Ultrasonic Diagnosis of Thyroid Nodule in Different Locations.

PURPOSE: To investigate the value of anteroposterior-to-transverse ratio (ATR) and the effect on features of nodules in ultrasound (US) diagnosis of thyroid nodules in different locations.  Methods: The nodules were divided into three groups according to the different nodule location: isthmus group; upper and lower poles of bilobed thyroid group; and the middle of the bilobed thyroid group. The diameters of the nodules were recorded, and ATR of the nodule was calculated on the transverse and longitudinal sections. The transverse and the longitudinal sections of ATR of thyroid nodules in different groups were compared.  Result: The transverse section of ATR was significantly different among the three groups (p = 0.001). In addition, there are significant differences in many US features among three groups, including nodule composition, thyroid parenchyma, morphology, echogenicity, shape, calcifications, vascularity, nodule ACR TI-RADS and histopathologic (all p < 0.05). In the group of upper and lower poles of bilobed thyroid, significant difference was found between the transverse and the longitudinal section of ATR (p = 0.019). The cut-off values of transverse section and longitudinal section of ATR were 0.967 and 0.750, respectively.  Conclusion: The transverse section of ATR at different location of thyroid may be a predictor for malignancy with clinical diagnostic significance.

Turning the Tap: Conformational Control of Quantum Interference to Modulate Single-Molecule Conductance.

Together with the more intuitive and commonly recognized conductance mechanisms of charge-hopping and tunneling, quantum-interference (QI) phenomena have been identified as important factors affecting charge transport through molecules. Consequently, establishing simple and flexible molecular-design strategies to understand, control, and exploit QI in molecular junctions poses an exciting challenge. Here we demonstrate that destructive quantum interference (DQI) in meta-substituted phenylene ethylene-type oligomers (m-OPE) can be tuned by changing the position and conformation of methoxy (OMe) substituents at the central phenylene ring. These substituents play the role of molecular-scale taps, which can be switched on or off to control the current flow through a molecule. Our experimental results conclusively verify recently postulated magic-ratio and orbital-product rules, and highlight a novel chemical design strategy for tuning and gating DQI features to create single-molecule devices with desirable electronic functions.

Heme oxygenase-1 enhances autophagy in podocytes as a protective mechanism against high glucose-induced apoptosis.

Injury and loss of podocytes play vital roles in diabetic nephropathy progression. Emerging evidence suggests autophagy, which is induced by multiple stressors including hyperglycemia, plays a protective role. Meanwhile, heme oxygenase-1 (HO-1) possesses powerful anti-apoptotic properties. Therefore, we investigated the impact of autophagy on podocyte apoptosis under diabetic conditions and its association with HO-1. Mouse podocytes were cultured in vitro; apoptosis was detected by flow cytometry. Transmission electron microscopy and biochemical autophagic flux assays were used to measure the autophagy markers microtubule-associated protein 1 light chain 3-II (LC3-II) and beclin-1. LC3-II and beclin-1 expression peaked 12-24h after exposing podocytes to high glucose. Inhibition of autophagy with 3-methyladenine or Beclin-1 siRNAs or Atg 5 siRNAs sensitized cells to apoptosis, suggesting autophagy is a survival mechanism. HO-1 inactivation inhibited autophagy, which aggravated podocyte injury in vitro. Hemin-induced autophagy also protected podocytes from hyperglycemia in vitro and was abrogated by HO-1 siRNA. Adenosine monophosphate-activated protein kinase phosphorylation was higher in hemin-treated and lower in HO-1 siRNA-treated podocytes. Suppression of AMPK activity reversed HO-1-mediated Beclin-1 upregulation and autophagy, indicating HO-1-mediated autophagy is AMPK dependent. These findings suggest HO-1 induction and regulation of autophagy are potential therapeutic targets for diabetic nephropathy.

Ferroics in Hybrid Organic-Inorganic Perovskites: Fundamentals, Design Strategies, and Implementation.

Hybrid organic-inorganic perovskites (HOIPs) afford highly versatile structure design and lattice dimensionalities; thus, they are actively researched as material platforms for the tailoring of ferroic behaviors. Unlike single-phase organic or inorganic materials, the interlayer coupling between organic and inorganic components in HOIPs allows the modification of strain and symmetry by chirality transfer or lattice distortion, thereby enabling the coexistence of ferroic orders. This review focuses on the principles for engineering one or multiple ferroic orders in HOIPs, and the conditions for achieving multiferroicity and magnetoelectric properties. The prospects of multilevel ferroic modulation, chiral spin textures, and spin orbitronics in HOIPs are also presented.

Clinicopathological differences between classical schwannomas and cellular schwannomas in the retroperitoneum.

This study aimed to compare clinical and pathological features of retroperitoneal classical schwannomas and cellular schwannomas. A total of 64 cases of retroperitoneal classical schwannoma and 48 cases of cellular schwannoma were studied. Histopathological analysis was performed using hematoxylin and eosin staining and immunohistochemistry. Retroperitoneal cellular schwannomas exhibited 100% (48/48) and 75% (36/48) positive expression for glial fibrillary acidic protein (GFAP) and cytokeratins (CK), respectively. Classical schwannomas showed rates of 6.25% (4/64) and 15.63% (10/64), respectively (P < .05). In classic schwannomas, 85.9% (55/64) showed a reticular pattern of positive anti-CD34 staining around tumor margins and subcapsular areas vs 52.1% (25/48) in cellular schwannomas (P < .05). Cellular schwannomas exhibited more mitotic figures than classical schwannoma (P < .05). The recurrence rate of cellular schwannomas was 10.42% (5/48), while that of classical schwannomas was 1.56% (1/64) (P < .05). Retroperitoneal cellular schwannomas commonly express GFAP and CK compared to classical schwannomas, suggesting that cellular schwannoma may originate from unmyelinated Schwann cells, while classical schwannoma may originate from myelinated Schwann cells. Anti-CD34 staining patterns may be used to distinguish between the 2 types. Retroperitoneal cellular schwannomas also show higher mitotic activity and are more prone to recurrence.

Quality assessment of paediatric education and research in southwest China: A cross-sectional study.

Currently, there is a limited analysis of medical education research both domestically and internationally. To enhance, improve the quality of medical education, this study conducted a quantitative analysis of teaching project data from an affiliated hospital during the period 2016-2022. The results indicated that a total of 133 teaching projects were initiated during this period, with an average age of project leaders being 42.73±6.45 years. Regarding professional ranks and titles, municipal-level project leaders had a high concentration of seniors (48.15%), while at the university-level, most project leaders held the title of deputy seniors (58.82%). At the university-level, project leaders were mainly distributed between deputy senior titles (37.08%) and intermediate titles (38.20%). In terms of research content, nearly half of the studies (46.62%) focused on teaching methods and models. Further regression analysis revealed that professional ranks and titles were an independent factor influencing the project level (P<0. 05). These findings suggest the need for improvement in medical education research, including addressing the uneven distribution of research topics, enhancing the research capacity of junior and mid-career medical education teachers, and improving the dissemination of research results.

Exercise preconditioning improves mesenteric lymphatic contractility through MAM in rats following hemorrhagic shock.

ABSTRACT: Restoration of mesenteric lymphatic microcirculation is crucial for alleviating severe hemorrhagic shock-induced death. Exercise preconditioning (EP) enhances adaptability and resistance to injury and disease. The mitochondria-associated endoplasmic reticulum membrane (MAM) plays a crucial role in the energy and information exchange between the two organelles. Therefore, we hypothesized that EP ameliorates mesenteric lymphatic contractility through MAM in rats following hemorrhagic shock, aiming to confirm that EP enhances resistance to hemorrhagic shock and further popularizes the idea that exercise is beneficial for health. To test this hypothesis, we observed the effects of EP for four weeks on survival time and mesenteric lymphatic contractility in conscious rats following hemorrhagic shock, and further explored the effects of MAM agonists and inhibitors. The results showed that EP prolonged the survival time and improved the mesenteric lymphatic contractility and reactivity in vivo and in vitro in rats underwent hemorrhagic shock, ameliorated the MAM ultrastructure in lymphatic smooth muscle cells (LSMCs) and reduced the voltage-dependent anion channel 1 (VDAC1, a vital protein of MAM) and IP3R1 expressions in mesenteric lymphatic tissue. Importantly, treatment with 2-APB (IP3R1 inhibitor) or VBIT-12 (VDAC1 inhibitor) prolonged the survival time, improved mesenteric lymphatic contractility in vivo, ameliorated the MAM ultrastructure injury, and decreased the IP3R1 or VDAC1 expressions in LSMCs in rats following hemorrhagic shock. In contrast, the administration of drinking water containing CdCl2 (IP3R1 activator) abolished the beneficial effect of EP on hemorrhagic shock. Taken together, the protective effect of EP on lymphatic contractility following hemorrhagic shock was achieved by improving MAM in LSMCs.

Chiral multiferroicity in two-dimensional hybrid organic-inorganic perovskites.

Chiral multiferroics offer remarkable capabilities for controlling quantum devices at multiple levels. However, these materials are rare due to the competing requirements of long-range orders and strict symmetry constraints. In this study, we present experimental evidence that the coexistence of ferroelectric, magnetic orders, and crystallographic chirality is achievable in hybrid organic-inorganic perovskites [(R/S)-ß-methylphenethylamine]2CuCl4. By employing Landau symmetry mode analysis, we investigate the interplay between chirality and ferroic orders and propose a novel mechanism for chirality transfer in hybrid systems. This mechanism involves the coupling of non-chiral distortions, characterized by defining a pseudo-scalar quantity, ξ = p ⋅ r ( p represents the ferroelectric displacement vector and r denotes the ferro-rotational vector), which distinguishes between (R)- and (S)-chirality based on its sign. Moreover, the reversal of this descriptor's sign can be associated with coordinated transitions in ferroelectric distortions, Jahn-Teller antiferro-distortions, and Dzyaloshinskii-Moriya vectors, indicating the mediating role of crystallographic chirality in magnetoelectric correlations.

Two-dimensional chiral perovskites with large spin Hall angle and collinear spin Hall conductivity.

Two-dimensional hybrid organic-inorganic perovskites with chiral spin texture are emergent spin-optoelectronic materials. Despite the wealth of chiro-optical studies on these materials, their charge-to-spin conversion efficiency is unknown. We demonstrate highly efficient electrically driven charge-to-spin conversion in enantiopure chiral perovskites (R/S-MB)2(MA)3Pb4I13 (〈n〉 = 4), where MB is 2-methylbutylamine, MA is methylamine, Pb is lead, and I is iodine. Using scanning photovoltage microscopy, we measured a spin Hall angle θsh of 5% and a spin lifetime of ~75 picoseconds at room temperature in 〈n〉 = 4 chiral perovskites, which is much larger than its racemic counterpart as well as the lower 〈n〉 homologs. In addition to current-induced transverse spin current, the presence of a coexisting out-of-plane spin current confirms that both conventional and collinear spin Hall conductivities exist in these low-dimensional crystals.

The accuracy of ultrasound-guided fine-needle aspiration and core needle biopsy in diagnosing axillary lymph nodes in women with breast cancer: a systematic review and meta-analysis.

Background: This study evaluates the diagnostic accuracy of ultrasound-guided fine needle aspiration (US-FNA) and core needle biopsy (US-CNB) for detecting axillary lymph nodes in women with breast cancer. Methods: Eligible studies and pertinent literature resources were identified in Cochrane, PubMed, Embase, CNKI, VIP, and Wanfang databases using subject-specific keywords. Study outcomes were tested for heterogeneity, and meta-analyses were performed to estimate sensitivity, specificity, and diagnostic odds ratios (DORs). The summary receiver operating characteristic (SROC) curve analysis was also performed. Results: A total of 22 studies involving 3,548 patients were included to evaluate the diagnostic accuracy of US-FNA and 11 studies involving 758 patients were included to evaluate the diagnostic accuracy of US-CNB in identifying axillary lymph nodes in women with breast cancer. The accuracy of US-FNA in identifying suspicious axillary lymph nodes was as follows: overall sensitivity, 79% (95% CI: 73%-84%); global specificity, 96% (95% CI: 92%-98%); overall positive likelihood ratio, 18.55 (95% CI: 10.53-32.69); overall negative likelihood ratio, 0.22 (95% CI: 0.17-0.28); DOR, 71.68 (95% CI: 37.19-138.12); and the area under the SROC curve, 0.94 (95% CI: 0.92-0.96). The accuracy of US-CNB in identifying suspicious axillary lymph nodes was as follows: overall sensitivity, 85% (95% CI: 81%-89%); global specificity, 93% (95% CI: 87%-96%); overall positive likelihood ratio, 11.88 (95% CI: 6.56-21.50); overall negative likelihood ratio, 0.16 (95% CI: 0.12-0.21); overall DOR, 66.83 (95% CI: 33.28-134.21), and the area under SROC curve 0.96 (95% CI: 0.94-0.97). Conclusions: The results indicate that both US-FNA and US-CNB have high accuracy for suspicious axillary lymph nodes.

Ultrasound characteristics of abdominal vascular compression syndromes.

Abdominal vascular compression syndrome (AVCS) is caused by the compression of abdominal blood vessels by adjacent structures or the compression of abdominal organs by neighboring blood vessels. Such compressions can result in a variety of clinical symptoms. They are not commonly seen in ultrasound practices, and their presence may have been underrecognized and underdiagnosed. This article reviews the clinical features, ultrasound characteristics, and diagnostic criteria of four types of AVCS, namely, celiac artery compression syndrome, renal vein compression syndrome, iliac vein compression syndrome, and superior mesenteric artery syndrome to increase awareness of these conditions among ultrasound practitioners. The ultrasound criteria for AVCS are primarily based on studies with small sample sizes, and therefore, it is important to exercise caution if these criteria are used.

Corrigendum: Quantitative evaluation of post-stenotic blood flow disturbance in canine femoral artery stenosis model: An early experience with vector flow imaging.

[This corrects the article DOI: 10.3389/fcvm.2022.829825.].

Experimental study: using the continuous wave Doppler spectrum technique to detect left atrial pressure.

Background: This study sought to investigate the accuracy of estimating left atrial pressure (LAP) using the continuous wave Doppler spectrum of mitral regurgitation. Methods: Dog models of left atrial hypertension with mitral regurgitation were established with disposable biopsy forceps and the injection of melamine formaldehyde resin microsphere suspension. A total of 40 models of left atrial hypertension with different hemodynamic statuses were established by injecting either esmolol or dobutamine in which the spectrums of mitral regurgitation were clear and the regurgitation velocity exceeded 3.5 m/s. The continuous wave Doppler spectrums of mitral regurgitation were recorded and analyzed to estimate left atrial pressure (LAPECHO). The mean left atrial pressure (LAPC-MEAN), the isovolumic diastolic left atrial pressure (LAPC-IVRT), the maximum left atrial pressure (LAPC-MAX), and the minimum left atrial pressure (LAPC-MIN) were also measured using the catheter method in the same cardiac cycle. Results: The LAPECHO (mean ± standard deviation; 11.77±4.36 mmHg) was correlated with the LAPC-MEAN (11.51±4.77 mmHg; r=0.887, P=0.000), but the difference was not statistically significant (P=0.459). The LAPECHO was correlated with the LAPC-IVRT (12.16±4.72 mmHg; r=0.883, P=0.000), but the difference was not statistically significant (P=0.271). There was a correlation between the LAPC- MEAN and the LAPC-IVRT (r=0.987, P=0.000), and the difference was statistically significant (P=0.000). Conclusions: This study suggests that the ultrasound evaluation of LAP correlates well with LAP measured using the gold standard catheter method, and is a simple, convenient, non-invasive method to quantitatively estimate LAP. This method is promising, but further large-scale animal experiments and clinical studies need to be conducted.

Quantitative Evaluation of Post-stenotic Blood Flow Disturbance in Canine Femoral Artery Stenosis Model: An Early Experience With Vector Flow Imaging.

Objective: To investigate the value of Vector Flow Imaging (V Flow) in the assessment of post-stenotic turbulence in the canine arterial stenosis model. Materials and Methods: Canine femoral artery stenosis models were established using ameroid constrictors in 12 beagle dogs. 50% and then 70% femoral artery stenoses were confirmed by selective femoral artery angiography. V Flow was used to measure femoral artery flow turbulence index (Tur) preoperatively as a baseline. After establishing of a 50% and then 70% stenoses, the Tur indices were recorded in the femoral artery at 1, 3, 5, 7, 9, 11, 13, 15, 17, and 19 mm distal to the stenosis. Results: Baseline Tur indices of normal canine femoral arteries were <1% in 11 of 12 cases (91.7%). Distal to a 50% stenosis, the Tur index (>1%) was recorded in 83.3-100% cases between 1 and 9 mm, 41.7-58.3% between 11 and 17 mm, and 16.7% at 19 mm. For a 70% stenosis, the Tur index (>1%) occurred in 81.8-100% cases between 1 and 17 mm distal to the stenosis, and 63.6% at 19 mm. The Tur index peaked around 7 mm or 2.3 times of the initial vessel diameter (3 mm) downstream for a 50% stenosis and 11 mm or 3.7 times of vessel diameter downstream for a 70% stenosis. Conclusion: V Flow with Tur index measurement adds quantitative information of post-stenotic turbulence when assessing an arterial stenosis with ultrasound. Tur index of 1% seems a useful threshold for assessment of flow turbulence in this small sample study. Further studies with larger sample size are needed to evaluate the value of V Flow in clinical applications.

Calculation of left ventricular diastolic time constant (Tau) in dogs with aortic regurgitation using continuous-wave Doppler spectra.

OBJECTIVE: To investigate a new noninvasive method for calculating left ventricular diastolic time constant (Tau) through a continuous-wave aortic regurgitation Doppler spectrum. METHODS: According to ultrasound guidance, twenty-four animal models (beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB (MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals, (t2-t1) and (t3-t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau (Tau-D) was resolved and compared with catheter-derived Tau (Tau-c). RESULTS: There is no significant difference between Tau-D and Tau-c (45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively; P > 0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship ( r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement. CONCLUSIONS: This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.

Sonographic findings of hepatic venous gas in association with spontaneous rupture of a Klebsiella pneumoniae liver abscess: a case report.

Hepatic venous gas (HVG) is a very rare ultrasonic finding, and it is defined as abnormal accumulation of gas in the hepatic venous system. Various diseases can cause HVG, and femoral venous catheter is the most common cause. We, herein, present the case of a 79-year-old female patient with HVG that was caused by spontaneous rupture of a Klebsiella pneumoniae liver abscess. This was first found by bedside ultrasonography. On the basis of the blood culture results, imipenem-cilastatin and cefoperazone sulbactam were administered and the effect was acceptable. After 41 days of antibacterial and symptomatic treatment in the hospital, the patient had recovered well and was discharged. All of the previous reports on HVG have been summarized by thoroughly reviewing the previous published work. Overall, this is the first patient with HVG in association with spontaneous rupture of a K. pneumoniae liver abscess, and it might provide insights for future studies regarding the treatment of this disease.

Room-temperature quantum interference in single perovskite quantum dot junctions.

The studies of quantum interference effects through bulk perovskite materials at the Ångstrom scale still remain as a major challenge. Herein, we provide the observation of room-temperature quantum interference effects in metal halide perovskite quantum dots (QDs) using the mechanically controllable break junction technique. Single-QD conductance measurements reveal that there are multiple conductance peaks for the CH3NH3PbBr3 and CH3NH3PbBr2.15Cl0.85 QDs, whose displacement distributions match the lattice constant of QDs, suggesting that the gold electrodes slide through different lattice sites of the QD via Au-halogen coupling. We also observe a distinct conductance 'jump' at the end of the sliding process, which is further evidence that quantum interference effects dominate charge transport in these single-QD junctions. This conductance 'jump' is also confirmed by our theoretical calculations utilizing density functional theory combined with quantum transport theory. Our measurements and theory create a pathway to exploit quantum interference effects in quantum-controlled perovskite materials.