Mergers and acquisitions

7/207AC Technologies Inc.3M Co.3M Co., through its New Ventures Business unit, has Woburn, Mass.Maplewoodinvested in 7AC Technologies, a developer of heating, ventilation and air conditioning systems that use liquid desiccant technology to remove humidity from the air.7/20HI-Tech ManufacturingPrivate investorsA group of private investors that includes the Pohlad Schiller Park, Ill. family has acquired Hi-Tech Manufacturing, a maker of metal-cutting machine tools. 7/23The Integra Group Inc.NAMSANorth American Science Associates Inc. (NAMSA) has Brooklyn ParkNorthwood, Ohioacquired the Integra Group, a medical research firm.7/24Histogenics Corp.Multiple investorsHistogenics, a maker of medical regenerative products, Waltham, Mass. completed a $49 million financing round from an investor group that includes Eden Prairie-based Split Rock Partners.7/24Polaris Industries Inc.Eicher Motors Ltd.Polaris entered into a 50-50 joint venture with Eicher Motors MedinaNew Delhi, Indiato develop and market new vehicles in India and other emerging markets.7/25Center for DiagnosticInsight Medical ImagingInsight Medical Imaging has acquired MRI imaging services Imaging Inc.Edmonton, Albertaprovider Center for Diagnostic Imaging Inc. for $91 million. St. Louis Park 7/25BDM Consulting Engineers &MSA ProfessionalMSA Professional Services has acquired BDM Consulting, Surveyors PLCServices Inc.a provider of engineering services. St. PaulBaraboo, Wis. 7/26Public Radio InternationalWGBH-TV/BostonWGBH-TV/Boston will acquire Public Radio International, MinneapolisBostonwhich will become an independent unit of WGBH.